Cost is a slight issue?
Honestly, including tools I don't think you stand much of a chance with that budget. Assuming you have nothing (since all you mentioned was the iron) you'll need a drill, drill bits, solder, cutters, wire strippers, wire, and I'm sure some other stuff I'm forgetting. Now even if you go super cheap with that stuff you'll likely eat up half your budget or more and that's if you can source it all locally and avoid shipping charges. So if we're left with $50 about the only thing you can build for that is a Cmoy which doesn't seem to fit with your "I don't want a learning experience" mantra. About the only thing that you could build outside of an amp would be cables, which actually could be done within your budget since it would limit the number of tools that you'd need and the supplies are much easier to source.