After having the night to think about it, I decided that since I'm planning to race this bike this season and log many, many miles on it, I don't want to start down that path with parts of questionable vintage in the most important places.
As such, this morning I ordered the Praxisworks BB30 conversion for Shimano cranks. I opted for the more expensive unit with ceramic bearings because dammit I want to be done repairing this thing. And since the crankset has to come off to install it, I picked up an Ultegra 6700 39t chainring to replace the old 5600-series 105 ring.
It was kind of crazy pricing out inner 39t rings, as both the 5700-series 105 and 6700-series Ultegra came in at about $12, but the Dura Ace 7900 was consistently $50 all over the Internet. I'm not so big a Fred that I have to run Dura Ace on an inner ring, and $12 is a pittance to ensure longevity.
Almost immediately after hitting the "order" button I flew into a bit of a panic. I've replaced so much of this bike...should I have just gotten a new one back in August? Because I am exceptionally anal, I was able to pull together every single receipt for parts and labor, and while I've spent almost as much repairing it as buying it, I'm still riding a hi-mod carbon bike below the purchase price of a similarly-equipped new bike from ANY of the mid- to high-end brands on the market, already fitted with crazy light wheels. And best of all? It's gorgeous. I'll take that any day.
In other exciting cycling news, yesterday was 'free money day' at Performance Bicycle, as they dropped the price of my winter bike by $100 for the second time in the 3 months since I bought it. Yay free money!