I follow the Japanese bass market very closely and have purchased from there. You're fine if you buy from a real store (Kurosawa, Ikebe, Ishibashi, Blue Guitars, Bass Geek in Box, etc.) - or Danny J. Stewart at Bass Japan Direct. If you know where to look, you can correlate their listings to (I forget exact url but it's something like) digimart which seems to track more or less the flow of instruments from manufacturers to legit dealers.
As you note it's the re-listers to watch out for, you can find the exact same pix/description from multiple entities on eBay, and more and more on Reverb. From my understaning it's not necessarily a scam per se, BUT you're trusting some rando to make a transaction on your behalf, take care of logistics, and fix problems with shipping, packing, customs, etc. if things go awry. They have to be taking a cut along the way.
Back OT, probably best to buy sooner than later even if prices just went up...