I'm a manga collector, but I don't exactly go overboard
(no matter how much I'd like to!). I guess I mean that I get as much as I can as long as there's not too much overlap.
I have every Toriyama manga volume that's available in English and Japanese (DB, Slump, One-shots, etc), and some art books like a few volumes of the Daizenshuu, Tocchio the Angel, and Toriyama The World Special. However I just own the (original) Tankobon editions of the manga. I have the itch that makes me want to collect the Kanzenban, but haven't succumbed yet, mostly due to financial limitations, but also maybe a little bit of common sense
But boy, when I first found out about the Kanzenban I was like like, "Oh...new covers, wow! WAIT -- A NEW SPINE ILLUSTRATION!?! Now I really want it!" It's funny what sets us off, ha ha!
I started collecting the VizBigs and while I felt a little silly collecting the series for a 3rd time, I justified it by telling myself the quality was better and the color pages were a big thing. THEN when I realized that not ALL of the color pages were reprinted in color in each edition (plus noticing some censorship) I decided to drop them. I only have the first 2 volumes of both VizBig DB & DBZ. I've got a few Daizenshuu, which reprints the color pages so I figured I was good there.
So the big hole in my collection are all of Toriyama's uncollected one-shots. I bought the recent 2-volume One-shot collections, which had quite a bit of overlap with the Toriyama Theater books, but they had some new stuff so I bought them immediately. The next step I guess would be tracking down Jumps on ebay or something, I suppose. But, again, it just doesn't fit into my budget to be hunting those down at the moment.
I guess my philosophy is that what I'm most interested in are the products of Toriyama literally putting his pen to paper and creating something. I like the DB & Slump anime, and figures and stuff are neat, but it's the Toriyama manga and artwork that I really pursue. That's why I haven't tracked down Naho Oishi's work, and why the first two volumes of the Daizenshuu were the ones I wanted the most, and things like that.