I had some old RSX brifters on my '86 Trek road frame. For a 20+ year old part, it did a fine job. For newer groupsets, I prefer Tiagra to build up commuter, everyday-type bikes. I find they are the best balance between quality and cost. For your price range, you'll be able to get a nicer groupset if you buy an older bike. Even though you have 16-27 gears, you'll really only be using 5-6 of those most of the time unless you're using the same bike for all sorts of terrain. IMO, for city riding, you don't need 27 gears to get around. For perspective, I ride a single speed in a relatively flat city with occasional 3-8% grades.