I'm not an expert, but I've got a soft spot for Slingerland blakrome. Here's my take:

Price seems fair given that the drums are 3-ply and cymbals are included (the hats are pictured, but not described—do they come with it?). Slingerland HH stand isn't that rare: they show up on eBay and CL fairly regularly. Super Set-O-Matic tom mount is an improvement over the original S-O-M mount.

But I would try to dicker based on condition of the finish, missing bottom rims for the toms, and/or what appear to be non-stock bass drum rims. Sticksaver rims and tension rods are readily available, but they're an added cost.

I had to buy bottom rims when I acquired my Blakrome set. It was worth it—I'm really happy with how they sound.