When I've got questions about what something's worth, I often look at completed auctions on eBay.
HERE is a listing for a 1983 Tama Imperialstar 7-piece set with concert toms, very similar to the pics you posted, but with two fewer toms and no cymbals. It sold for about $250, plus $150 for shipping.
There are a few things working against the seller. First of all, they're concert toms, meaning the toms don't have a resonant (bottom) head. These were somewhat popular in the '70s and early '80s, but haven't had much of a following since. They can sound fine, particularly for rock music, but the lack of a resonant head limits your tuning possibilities. Concert toms also tend to get damaged along the bottom edge or go out of round. Secondly, the kit includes a few cymbals, but they're B8's, which have virtually no resale value on the used market. (Especially a crash that's been inverted?!)
As for being Japanese... In the '60s and '70s, quite a few cheap "stencil" kits of dubious quality were made in Japan by Pearl and Star, which became Tama. (Yamaha's early kits were pretty decent, though.) Since then, those companies have changed their approach and really make some quality gear. "MIJ" drums really don't (or at least shouldn't) carry a stigma unless we're talking about the cheap stencil kits.