I have no local small camera stores that I know sell Pentax SLR/DSLR locally. The big box electronics stores, if they have anything at all, are mostly staffed by people without much background knowledge.
I use Amazon or B&H a lot on line (both very reliable, easy return if there is a problem, reasonable prices). For an ebay seller, I've had really good service and good prices from The Imaging World if they have it (authorized dealers but very limited range of stuff). Paypal with the little Verisign key is pretty safe and anonymises the account/card info.
If you are buying anything online (especially camera/ electronics related), first check the site out well through Reseller Ratings
Store Ratings and Reviews by Real People - Trusted Online Shopping. And for fun and education try this collection of photos (
Brooklyn StoreFronts) before you buy from the "cheap" Brooklyn stores (there are a few good Brooklyn stores too, though).
Kevin.