Warning - looking at others beautiful bikes is CONTAGIOUS!
Test your patience and instead, let interesting bikes find you. Also, the word 'cheap' means different things between others. Various means of acquiring have been by Goodwill, throw-aways by the curbside, gifted, estate auctions (where the buyers main interest is furniture and other articles), shared knowledge or talking of cycling while in other hobby / interest groups and yes, even LBS's. Many LBS don't bother with an old bike, nor want to re-sell or service. Have fun!