I know you said you already checked the chain stores, but I found one at Target last weekend. (My husband talked me out of buying it because it was $9.99 with $6.99 filter refills.) Anyway, I found it near the food plastic containers (Rubbermaid, Sterilite, etc.). It was literally wedged between the different containers, so it was easily overlooked. I don't remember the brand name, but it was in a med. blue and kelly green color scheme and it holds 20 oz of liquid. I just looked on Target.com, but it wasn't there, so you'll have to go into the store to find it. If I go to Target in the next day or so, which is very possible, I'll make note of the brand name and post it here.
Just wanted to let you know that Target (here, on the west side of Madison) does carry a more reasonably priced filtered water bottle than you have apparantly found. Good luck and I'll try to remember to get more details on this bottle for you. :wave: