I like to keep a few "consumables" in stock, especially things like brake and derailleur cables, so I don't run to the LBS every time I need one (and may have my bike hobbled). I changed to Stainless Steel recently as it seems a little slicker than the Galvanized, and hopefully less prone to corrosion.
Since I buy in advance, I can do direct Chinese orders for $1 to $2 per cable, or less. E-Bay is your friend. I still buy them several at a time.
I used to put a little ball of solder on the cable ends. :However, the last time I tried with Stainless, I had a lot of troubles getting the solder to stick. I noticed the new cables I was getting were welded, so I've now started tig welding my cable ends.
For years I've used unlined cable housings. I now bought some teflon lined cable housing, 25 ft rolls off of E-Bay for dirt cheap. We'll see how they last. I usually get 10 to 20 years out of my unlined cables, but have heard of people getting less than a year out of lined cables... pretty scary thought. If that is true, I'll look for something else.
Chains also from E-Bay, $10 to $11 each for HG-73 chains (Shimano 9S). I have some replaceable pins somewhere, but I got 2500 miles out of my last chain pushing the pin back in. I marked the pin on the new chain I just mounted... I think. Anyway, I coudn't find my pins so I just pushed it back in for another test.
I usually just re-use my bearings. However, I decided to try some E-Bay ceramic bearings in one hub. So far, so good... I think
I bought several tubes with my last Ribble order, $3.33 each, although I will frequently pick up some at a LBS or dept store (assuming they have them in stock, it isn't uncommon for narrow 700c tubes to be out of stock).
I did pick up some extra tires for my projects, but I don't really want to buy them too far in advance as I don't want the rubber drying out.
I've got some import bar tape on the way. I don't know what to expect. I may end up buying some Fizik 3mm tape sometime soon. A little more expensive, but hopefully good stuff.