Drew Eckhardt 

I spend most of my money on tires, chains, and shorts as they wear out. Rarely I wear out a bottom bracket (12,500 miles due to excessive preload), shifter (25,000), or cassette (25,000+). I bent a few 400g Mavic Reflex clinchers, although the more durable rims I switched to have held up.

No, but those reasons have nothing to do with it.

Obsolescence isn't a thing for road bikes unless someone is trying to sell you a new one. My 1997 titanium frame fits and rides as well as the day I first built it 23 years ago, and would accept an 11 or 12 cog electronic group if I felt like that. I have matching spares for everything except brake calipers which I'll pickup before they become too collectible.

Crashes aren't an issue. You'll break before a metal frame does, and they're weldable to be as good as new when that happens. I'd be happier if I didn't occasionally feel my sprained AC joint from when I crashed and broke my clavicle.

Theft isn't an issue. You keep it indoors and pay a few dollars for renters/home owners replacement value coverage.

For $4000, you're paying extra for a brand name or cosmetics. Nelson Titanium Products custom titanium frames made in San Francisco start at $1800. San Francisco is not an inexpensive city.

Probably.

You want shorts with comfortable chamois and jerseys which fit both short and long sleeve.

I'm fond of the Elastic Interface Technology Comp HP chamois which feels great past 200 miles. You can get those in Voler shorts for $139, and bibs (other than size samples) somewhat more. With a 26-28" waist I wear small shorts, at 5'10 with a 30" pants inseam XS jersey length is an issue for me, non-custom bibs aren't an option, and I like the Comp HP chamois more than Boure's offerings. Assos and Rapha also use EIT chamois, but you can get better deals from companies catering to the custom market for teams and clubs.

I have race fit thermal jerseys for every day of the week in winter. They are super comfy and worth $89 each apart from the $19 United Health Care team left over.

Most of my summer jerseys are previous year custom program size samples which fit for $25 in regular race fit and $45 for aero.

Sometimes. More cogs give you tighter spacing or more range. Electronic shifting means no cable replacement, going directly to the next gear on the other ring without running Campagnolo mechanical, and perhaps extra shift buttons where you want them. Disc brakes don't eat rims annually in the Pacific Northwest. Carbon brake levers are more comfortable in cool weather that's not cold enough for gloves. Beyond that, a more expensive group doesn't give you additional functionality, just weight and cosmetics. One pound off a 150 pound bike + rider combination is 20 seconds an hour in the mountains (less if you're not built like Alberto Contador). That matters if you're racing or close to earning your 1 hour Mt. Diablo Challenge T-shirt. Otherwise it doesn't.

The performance difference between decent aluminum and carbon is small and could go either way at low yaw angles. As the cross wind component increases, at 20 MPH you're looking at a couple of watts. A bad 25mm+ deep rim might reach 12W at high yaw angles and 30 MPH, although that's out of 600-700 total. Manufacturers publishing numbers use the venerable Open Pro which was slow 20 years ago as a benchmark, use uncommon yaw angles, and measure at 30 MPH requiring over triple the power of a fit recreational cyclist's 20 MPH solo pace.

I built a pair of wheels with retroreflective powder coating for night riding, dynamo front hub to run lights and GPS for long rides outside daylight hours, and PowerTap rear power meter which works with any crank and pedals. That's a big win in enjoyment.

Enough to get what I wanted. I paid $2200 total in 1997 for a straight gauge Litespeed titanium frame built the way I wanted it with Campagnolo components (mostly Chorus, because I wanted ball bearing shifters and hubs with grease ports). 9 cogs cost me a couple of freehubs and a shifter cam adding to $250 when Campagnolo discontinued my favorite 8 speed cassette in 2000. The move to 10 cogs was about $700 in NOS and used parts circa 2014 when I broke a discontinued shifter spring. I have about $1100 in the wheels starting with a new SON28 front hub from Germany and NOS PowerTap SL+ in back. My $300 fit (parts not included) with video was totally worth it for comfort. To my surprise, the right angles also made pedaling feel easier.

I've ridden it everywhere - commuting even in snow storms (27mm cross tires fit), skydiving with rig on a BOB Yak trailer, Grand Junction to Golden, on unsupported solo 100-200 mile recreational rides. I eschewed bike computers from when my purple Avocet broke to 2010, although it's been 34,000 miles since then including the years when I was lazy.

Today I'd spend $3000 on a sporty custom frame with rack eyelets, longer chain stays for pannier heel clearance, and travel couplers. I'd be torn between a 2006 10 speed Campagnolo Record triple group (the titanium hardware and coated front derailleur color coordinate with a titanium frame) with 2010 Centaur Carbon levers and 12 speed electronic SRAM or Campagnolo (cassettes with no 18 cog, and finding a good shifting 42-30 or 40-28 crank to pair with a 10 or 11 starting cog are the hangups). I'd do the same thing with wheels. Probably rim brakes to allow splitting the cables with the frame. That's probably $4500 - $6500 depending on whether I raid my spare parts box, buy a used but not yet vintage gruppo, or go with 12 cog electronic.

If I buy a sports car built for the street and track, it comes with trunk space for groceries. The Porsche 911 even has rear seats for small children. Audi and BMW sell sports sedans that handle great and will do 200 MPH (M5) seating four adults comfortably. It blows my mind that road bikes with accommodation for a laptop containing pannier are uncommon. If I'm going to ride the average 32 mile round trip American commute daily on a bicycle (over 7500 miles and 500 hours annually) , I want an enjoyable riding experience.

I also don't get cheap commuter bicycles. People don't buy Hondas with no lumbar support to spend an hour a day in during the week leaving their nice German sports sedan with heated + cooled leather seats in the garage for Sunday drives. With the average distance people live from work you're spending over twice that time on a bicycle and will get half your weekly commuting total doing a longer weekend ride on your nice bike.