Hmmm, I don't know. It probably varied by location and what year we're talking about as prices rose quickly during the boom but I think a low end 10-speed in the early 70's was more in $65 - $75 range and available at your freindly neighborhood hardware store, auto parts store, or department store. $100 would get you a decent quality entry level bike from a respected European manufacturer. $140 - $175 would get you a nicer bike two to three models up from there but still hi-ten steel. Maybe in the $175 - $200 range you could start to find some 531 straight gauge bikes. $250 was a lot of money in 1972 and $500 was unthinkable for most people I knew to spend on a bicycle. That was a nice used car or downpayment on a new one. There's a joke here in Colorado that you can tell a native by the $5000 bike strapped on the top of his $500 car and I guess there have always been folks willing and able to spend the money to get something they really wanted. But I'd still argue that a heck of a lot more bikes in the $100 - $200 range were sold, ridden, and enjoyed back then than the over $200 bikes and those bikes were not department store junk bikes but decent bikes that you would find at a quality bicycle shop. I'm still riding a UO8, Prestige derailleurs and all, with just the upgrade of alloy rims and cotterless crank and it's quite a nice ride, not at all what I would describe as low-end or junk or gas-pipe or whatever.