As a person who has a customer base that is mostly drug addicted, low income, no income, homeless persons, with no moral compunction against theft, I'll let you in on a little secret: Ain't nobody gonna ever value a shoddy looking bike. Period. That also means ain't nobody ever gonna come lookin' for it neither. Then, after they steal that "jalopy" they are going to add their own colors to it just in case you are in the neighbor hood. After that, they'll devalue it even more by trading any working bits to a buddy for some "good karma." The other scenario is any working bits will get themselves stolen while the thief sleeps. The rest will get broken through ignorance & good intentions in a random bored moment with inadequate/worn out tools in search of an "upgrade" whatever that means.
You have no idea how many times I've heard the same story: "It had brake pads when I went to sleep."...or a seat post, or a chain, or gears, or any other thing that can be removed by an Allen wrench set, a crescent wrench, a screwdriver, or a stolen pair of pliers. If it can be removed, a thief
will take it. One customer even had his headset stolen
First rule: A commuter that is left outside should have a total value less than or equal to $100.
Second rule: The value of the locks should exceed the value of the bike by 50%
That's not really hard to do.
A U-lock for the front wheel to the frame.
A U-lock for the rear wheel to the frame.
A U-lock for the frame through whatever immovable object you are locking to. (If one of the above 2 locks can go through the immovable object too, that's even better.)
Finally, a cable lock through the saddle rails securing the saddle/seatpost to the seat stays.
Rule 3: Observe the bike rack. Is secured with bolts? Thieves will disassemble the rack. Park away from the bolts. Does the rack have duct tape applied to it? If so, thieves have already cut the rack and are waiting for an opportunity to remove the tape holding the rack together & the bike secured there.
Quality stolen bikes tend to stick around a while. Generally they get traded intact from junkie to junkie for drugs before eventually ending up at a drug dealers house or "vultured" wholesale at the homeless shelter. The funny thing is "ain't nobody saw nuthin'" & they eventually come to me for all manner of repair.
A bike doesn't need to be expensive to be a nice riding commuter. Any vintage rigid mountain bike with 30 years of battle scars will do. Then re-pack the wheel hubs. Spend $20 on a replacement bottom bracket. Add in some $13 friction "thumbie" shifters to dissuade any thoughts of "value" and you are good to go.