Personally, I think a Tektronix TM 500 mainframe (or the more modern 5000 series) would be a better investment. You can get function generators, DMMs, frequency counters, power supplies and even oscilloscopes for them! The mainframes and the more common modules (DMM, PS, Counter) can be had for next to nothing on eBay. Some of the less common modules seem to be a bit more expensive, but deals can be had if you're patient.
Most of the plugins use off the shelf 74 series logic and schematics are available, so it's easy to repair.
Sent from my Tablet