[quote name='mkg12']wtf, did Deep Discount raise the prices on their manga recently? Not really a question, I am pretty sure they did.[/QUOTE]
They did
. A volume that would've been a MSRP of $9.99 was sold at ~$7.13 before, but now it's $7.99. It sucks because I really liked buying just a few mangas at a time from DeepDiscount with the free shipping. I'm not sure I'll use them anymore unless they have a sale, drop back to the old prices, or if I really want to just buy a single volume or two (but I may as well just stop by Borders in that case).
On a side note, I have had nothing but great experiences with AnimeNation.com. Their prices aren't amazing (~10% off retail usually), but I got a bunch of stuff during their Dark Horse sale, and each and every manga has been in pristine condition (and I bought A LOT of stuff). Conversely, some of the manga I've ordered from Amazon has been in less-than-stellar shape.
They ship really fast, unless they're restocking the book (which takes no more than a week usually), and they ship the stuff out as it comes in stock. Normally they charge for each shipment, but they have a free shipping coupon on orders $75+, in which case the shipping becomes like Amazon's (Amazon always ships out my stuff as it comes in even if I put the option to group into as few shipments as possible).
Another quality place is CubicMall.com, which another person mentioned in this thread. They carry ComicsOne/DrMaster stuff, and there are some really good clearance deals going on. I personally got KOF Maniax issues 1-8 for something like $10.
Finally, I've had good experiences with DiscountAnimeDVD. Yes, they sell bootleg anime, but all their manga's legitimate. Customer service is good, all books I've gotten have been in pristine condition (a pet peeve of mine is when it's all dinged up), and they regularly have sales on manga from various publishers (35% off Viz stuff currently). I wish it didn't take $99 for the free shipping though.