250 for the 50/2 is an awfully good price.
KEH is going to sell you a BGN one for about 400, which seems to be about as low as you can find one reasonably.
I love the lens and it's the best 400 I have ever spent on a lens without question even compared to the 60/2.8 Macro-Elmarit-R which is my other pick in this price range.
Yes the 50/3.5 is only about 100 dollars for a late one in really good shape (IMO the price doesnt differ enough on condition to justify a user one) and it's one of my absolute favorite lenses ever. But it's very limited.
If you dont mind Ill show you one from each on film so maybe you can see why I like them so much.
Wide (28 and wider) and Macro are where you will find the strength of the OM lineup, or so the popular wisdom goes. I am inclined to agree. I dont yet have my own wide collection built up but that's because macros are my favorite lenses and my 28/2 has sufficed.
Anyway, 50/2
Untitled by
redisburning, on Flickr
and 50/3.5
Untitled by
redisburning, on Flickr
yes the 50/2 compares well with the 4th/5th gen M Summicron or E55 R Summicron. Gary Reese did a paired comparison. Mike Johnston said the same thing on his blog (paraphrasing: "you will not find a better 50mm regardless of brand"). it is very good wide open and at f2 is about the best I have ever owned excluding 50MP which is in another class. I have not used 55 distagon, 50/1.4 lux asph, 50/2 AA, though. It beats ZM50P and DR Summicron and Rokkor 58/1.2 and Zuiko 50/1.8, 1.4 and 1.2 and it takes it to the edges.
The 50/2 has some unique characteristics to it. Maybe I should write an indepth article on it.