I was just at that Disney Character Warehouse outlet last week and it's absolutely GREAT - the prices are 50-70% less than at DL (my daugher bought the most ADORABLE Minnie rolling suitcase for $19.99; the EXACT SAME item in DL was about $38.99).
If you want a T-shirt or sweatshirt with "Disney" emblazoned on it, the Warehouse prices just can't be beat. The only disadvantage to the Warehouse is limited selection - there were lots of "out of season" items but since I'm from Canada, buying gloves in July isn't so pointless - LOL!!!! If you'lre looking for a specific item, you may be out of luck but it's certainly worth a look.
As for other stores in the Mall - Dollar Tree Stores Inc. provided some cheap souvenirs/toys (a.k.a. junk!!) for the kids, as did the "Factory 2-U Store" (where I got a steal of a deal on a hairdryer!). There's also a massive jewellery store on the corner and another one across the street (my husband whipped my credit cards out of my purse at this point!!).
As for souvenirs at DL - I thought the plush Minnie ears were quite reasonable at $7; my son bought a Pirates Sword at New Orleans Square for the princely sum of $3.75. Otherwise, I thought most of the toys, clothes, souvenirs a bit overpriced. Oh, and DON'T buy film at
Disneyland - I ran out and had to pay 60% more than I paid here in Canada (morale of this - take 6 more rolls of film than you think you'll need!!!).
My kids LOVED the squished pennies - next time I'll make sure I have a roll of nice, shiny brand new pennies with me especially for this purpose.
One final thing, if you can, break up your "Disney Days". Our second and fifth days (of a nine day vacation) were "Disney-free" but still my 5 year old daughter complained "Do we have to go to Disneyland EVERY day?" on our fourth visit to DL!!! Quite frankly, I was Disney-ed out by the fifth day too.
HTH and have a great trip!