No, absolutely not. Casey = not so good. It's too bad that he's the big ATW seller at the moment, but I refuse to buy his stuff, period. He even had NGBC a week or two ago for $900, but there's no way I'd buy from the guy. I know various people (around here, even) will vouch for him being a good seller all of a sudden (i.e. he sold a legit full kit Progear to Rot and Rot verified that it was legit), but there's no reason to believe he doesn't still scam people when possible.
That and he's a complete and utter tool. Browse for some Garysheffield posts and you'll see what I mean.
I bet you'll be able to find all of the titles that you listed, other than NGBC, relatively easily, probably even from members on here. DB goes for cheap (Devilredeemed sells bunches at a time sometimes, and for good prices), and GGX 1.5 is nowhere near as hard to find as it used to be. GGI is getting more and more common, too.
I think you should hopefully get enough response to this thread to avoid buying from Casey.
ps. DB is pretty damn fun- I got mine when they still went for over $200 (part of a package deal) and I haven't regretted it at all. Neowave is solid, and I haven't played GGX 1.5, but I have Isuka on ATW and I like it a lot. Good choices.