I think you'll find it's nice equipment. I've seen some of those cameras valued at about 8,000 to 18,000 yen (I live in Japan), though that's from memory, I was actually looking at the Dynax / Alpha 7 cameras. The 50mm 1.7 was the standard kit lens of that generation, it's pretty good (much, much better than any "kit lens" in this current digital generation), and so I've heard of that fetching anywhere from USD$80 to over $100; however, the 50mm 1.4 was the top lens of that generation, and is still really highly regarded now. The 2800 flash probably isn't worth much, now, having a low Guide Number (GN), and being for film, but would definitely be useful for some people. The rest, I don't know much about myself. I think I had the 35-80mm, it was the first of the zoom kit lenses, and it probably delivered good results, though nothing compared the the top rated G lenses of Minolta.
Anyway, I dare say the jewels in that treasure chest are the camera bodies and that 50mm lens. I think you might enjoy using them.