£300 is (to my mind) a tricky budget. It's not really enough to get an OTP bike, and buying a bike to convert can be an almost bottomless pit.
It's a fine budget for an OTP - Fuji Track is £276.95 and not a bad ride. Buying a bike to convert is in no way a bottomless pit, as long as you know what you are buying/looking for to start with.
For example my current project bike cost me £103, it's a 531C frame and forks, Campag Headset, Cinelli 66 bars, Cinelli 1A stem, Cinelli BB, Shimano chainset, Campag seatpost. A steal for 100 quid. The only mandatory big expense is a new rear (hub/spokes/rim/cog). As long as the frame, headset, bb and forks are sound there is no reason why a build should not be quite predictable in terms of cost...
It's a fine budget for an OTP - Fuji Track is £276.95 and not a bad ride. Buying a bike to convert is in no way a bottomless pit, as long as you know what you are buying/looking for to start with.
For example my current project bike cost me £103, it's a 531C frame and forks, Campag Headset, Cinelli 66 bars, Cinelli 1A stem, Cinelli BB, Shimano chainset, Campag seatpost. A steal for 100 quid. The only mandatory big expense is a new rear (hub/spokes/rim/cog). As long as the frame, headset, bb and forks are sound there is no reason why a build should not be quite predictable in terms of cost...