Originally Posted by Ironfish653

Again, I question the cost value in 'converting' a vintage bike as a 'budget' build. Do you have a stash of parts (or access to one) or will you be buying what you think you need to do this conversion? The parts to convert a drop-bar 'Ten-speed' with downtube shifters to a flat-bar bike with shift levers on the bars will probably run $75-$100, although with the current situation, getting parts is kind of a crapshoot.
Starting with an old $150 bike, and adding $100 in parts (provided it needs nothing else, like a tires, a chain, or a saddle) puts you at $250, which will put you into the range of a lot of 2000's era bikes, which are already set up the way you're looking for, won't require as much work (if any) and will probably be lighter, to boot.