Just my opinion, but you will be so much farther ahead if you get a complete bike. The best deals are ones that need a lot of TLC. You know, sitting in someones garage for the last 20+ years. There is a guy in my neighborhood that makes some disposable income by collecting scrap. He regularly brings me bikes he finds on the side of the road. Some have been halfway decent.
If you find the right LBS, sometimes they take in bikes either on trade or for parts. Ask if they have any old road bikes in the back. Sometimes they will part with them reasonable. Thrift stores, garage sales, flea markets, etc. The right deal will eventually come along if you can afford to wait. Maybe some cheap transportation is in order till the right thing falls in your lap??