I've owned a couple FT-50s and I'm going to say "no" to this one. You can buy a new FT-60R for about $150. So, that means you are talking about $75 for the FT-50.
Any FT-50 on the used market is going to be pretty old as the radio's been out of production for about 15 years. Handhelds often don't get treated well by even the most careful person, so, in my opinion, they depreciate faster than a mobile or base radio. The FT-50 was susceptible to corrosion on the PTT contacts which makes it hard to switch to transmit mode, the rubber cover for the PTT deteriorates and lets moisture into the radio, and the speaker/mic jack wears out over time resulting in poor contact.
If I wanted an FT-50, I might pay $50 for a very clean one. But, I don't think I'd pay $75.
Differences? The FT-60 has 10 times the channel memory space and has a more flexible memory bank system. The FT-50 is short and thick so holding one is like holding a squared-off potato. It makes a real lump in your pocket. The FT-60, by comparison, is a little taller and noticeably thinner.