hi all, i have this lens that is sort of rare i suppose or thats what i heard anyway. its a 53mm Super Angulon f4, a friend and i were going to do some trading on some camera gear that he has, we would both like to know the approx value of this lens, i have heard that its worth whatever someone is willing to pay for it, but i would like to know what other forum members would be willing to pay, say a 53mm sa in a compur shutter all shutter speeds sound up to par glass is very good. we would like an approx value so we will know how to trade, not much info on the 53 SA. he says that he feels its worth more than what i think, anyway your opinion is much appreciated. thanks in advance.