I think part of the problem (not just frame supplies but bike cost also) is people remember what they paid for a bike in x years ago and don't consider what that would cost in todays dollars: just for fun I looked up what all the bikes I have owned would have cost in todays dolars
1964 Red Coast to Coast single speed coaster brake $36 today $250
1970 Columbia 3 speed English racer $75 today $450
1972 Azuki 10 speed $150 today $800
1982 Nishiki olympic 12 $300 Today $700
1989 Miyata 1400 $900 today $1600
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Life is too short not to ride the best bike you have, as much as you can.