I think some of the criticism of people who buy cameras as collectors' pieces is a little misplaced. For the kinds of cameras that are likely to be potential users, there are plenty to go around. As for driving up prices, again for the cameras likely to be used regularly, I'm not convinced that's the case. It may be true for a pristine, boxed Leica M3, but then who would buy that to take it out and get it dusty and wet anyway? Taking the longer view, come the day when all the users have been used, the collectors' cabinets can then be plundered for examples that have been kept in suspended animation! For most cameras that we'd likely want to take out and shoot with, we're hardly talking mortgage money.
To return to the OP's question (which was only seeking advice on cameras he should have, not whether he should be collecting in the first place!) I'll throw in another - the Zenit E. Though no great shakes specification-wise, it provided a first step into the world of SLR photography for many teenagers like myself in the 1970s who couldn't afford a Pentax and wanted to move upmarket from something like a Halina Paulette.