It sounds like an Amiga 4000D/030 model which was one of the last models released by Commodore before they went under. It's the one I owned because I couldn't quite afford the 040 version as a college student. I'm not sure what the capture card is if it's Scala related it could have been from an infochannel on TV. Can you get more details.
Otherwise, I'd look at what the A4000D/030 is worth itself. eBay sells them for nuts prices. Is there an asking price already on this unit?