You're looking for a unicorn, friend. There are not that many of them, compared to the old corny kegs that used to be used for soda back in the day. I think Adventures in Homebrewing has 3g pin locks for $39, or you can buy new Torpedo kegs from several sources. Honestly, the $39 pin locks is the best deal I've seen in over a year of looking.
You may be better off getting a larger fridge or going full keezer. I went from a 4cu foot minifridge with 2 kegs (and only barely fit) to a 4 tap keezer and it was a good decision. I wasted a fair amount of time and money building the kegerator. Should have gone bigger at the start. YMMV, of course.