I agree JF. Most Thai restaurants in Vancouver over-charge for their offerings. Some of the better restaurants are not the well-know ones. One thing to look out for is ownership - of course, that's easier said than done for non-locals. Many Thai restaurants, like Thai House (eight locations? Yuk), owned and operated by a Chinese restauranteur just don't cut it according to local Thai-Canadians. Not unlike Wally's Hamburgers on Kingsway (puke).
Some of the smaller eateries like Boua Thai on Kingsway, Bann Wasana on Hastings, and even Pad Thai in Maple Ridge put many large ones to shame. One of the better known ones, Salathai on Burrard, consistently over-salts its dishes, and they are very over-priced. The Sweet Tooth Cafe at Nanaimo & Hastings doesn't look like a Thai restaurant (more like a fifties era greasy spoon), but it is owned by Thais and they serve up reasonably priced Thai dishes.
As always, Caveat Emptor!