FLM combo bulks/advice?

I don't understand why the used one have gotten so expensive lately. They are still available new (6 & 8 spyder kits) on UE, so its not like they are going away. I bought 3 sets of 6 and 1 set of 8 spyder diffs over the past 2 yrs and never paid more than $150, all in excellent shape. Now I'm seeing buy it now prices that start at $200, whats up with that?

Paying for them assembled (used) cause don't think they can assemble them correctly?