Audio Research D110 or D111

Does anybody know this vintage amp from ARC? I tried researching it online but nothing is coming up except from ARC Database. I just want to know its current market value and whether it's worth purchasing. Thanks for any info
I haven't got any true notion of it's value relative to what you see paid for some ARC solid states, of that era. I own(ed) a couple of broken ones. I have seen others including mine which have been very unreliable. Approach with caution, don't pay Mac money even those these sound better to my ears. My D100B made great bass it actually lasted a year or two. I liked it for its sense of brute strength though it's power rating was about the same as those and it preceeded these models by a year or two. These are much bigger physically with what appears to be the basic ARC philosophy - tons of capacitance but with an unusual added sophisiticated METERS section. I just tried to buy a D-120, but it was DOA. I paid $350 for a well used D-100B and was going to pay $400 for the D-120. I'll do some research.
Sorry, that amp for sale is actually D-350 and the asking price is $550. Do you have any more info on it? Thanks!
ARC started with the D110 then the next generation was the 110B then 111. Differences between them is obviously parts and I was told by an ARC engineer that the 111 uses ring emitter output transistors. The 110 and (B) are the same physical and power supply as the 350 but just one output module card vs. two in the 350. Also the 110's are biased with higher current.