I have a very nice Beseler 45MCRX enlarger and, up to now, I have worked with a Beseler 50mm lens, mostly for my 35mm negatives. However, I want to be able to begin enlarging different size negatives (6x6 up to 4x5) and I have been shopping for lenses. I notice that Nikkors and Schneiders demand a much higher premium than other brands on flea bay. What is the primary difference and are they really worth 3 and 4 times as much? I have been enlarging only to 8x10 so far but am looking at going larger than that with my 6x6 and 4x5 negatives. I want to get a nice lens (or lenses), and am not afraid to spend a little extra money for quality. But, I am not a rich man and I am living on a limited income. I am an amateur and I love what my hobby, but I am certainly not entertaining any thoughts of doing this for a living. Any thoughts on quality vs price for a dedicated, but poor, amateur?