Does anyone know the value of BEL 1001 MKV?

BEL 1001 MKV in good condition
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I've seen many go for between $1000 and $1500 each. At that price, they're near impossible to beat ... a pair of them as monoblocks are incredible sounding amps.
I would say because of the fact that they are no longer being made or serviced by the original manufacturer, the price should be in the range of $1,200 - $1,500 for a used unit in good condition. It's a great amp.
If you are in the US you might want to call Brooks Berdan in Monrovia, CA. They are a dealer but have a service department that has a lot of knowledge about BEL amps.
I would say about $1500 each. I would get a pair of monoblocks. The sound was way better than stereo, especially the huge soundstage of the monoblocks.

I have used them from MKIII all the way to MK V driving Thiels including the CS7.2. They are great amps. They were extremely reliable and never broke. Unfortunately the owner and designer passed away a few years ago.
Are you planning to sell this amp?