Yes, the SE-8 is an excellent model. Its the next model down from the top-of-the-line, SE-9, that was made by Sansui in the early-mid 1980's. The SE-8 looks very similar to the SE-9, but I believe it doesnt have the 'Compu-equalizer' functions as the SE-9 does to do an analysis of a listening room. Both of these models were offered in either black or silver.
Sansui did make other equalizers, the RG models, and also the SE models, for example, SE-300, which is a cheap, plastic product thats not very impressive. The SE-9, SE-8 models are really their best. Later in the 80's, Sansui updated them with the SE-99, SE-88 models.
As for $ value, well.., you certainly can get your $20 back that you bought for it. Hard to pinpoint an exact estimate of its value, so I suggest checking the current and completed auctions on Ebay. Look at the SE-9 auctions, and whatver those prices are, simply take a little bit off for an SE-8.
Re: your studio engineer friend: I am into recording equipment myself, and I have many backissues of the magazine, 'Modern Recording' from the late 70's thru 80's. That was a really great magazine. The SE-9 was actually reviewed in it in a 1982 issue which I have, and the SE-9 was looked upon very favorably.