Revox B 150 and B 160

I have been offered a trade for the Revox B 150 and B 160 and some other gear but can't find much information about the units. I would be trading about a $400 to $500 dollar receiver. Does anyone know much about Revox also I would probably just flip the two units is there a market for it?
there are many revox collectors out there...near mint condition with boxes,etc would be easy to sell.