I finally caved and bought a tiki dress on ebay. I've become obsessed with having one and I figure the odds of them having any in stock when I go in September are pretty slim. I found there are more ebay sellers now with reasonable prices - I paid $150 (including shipping) for my tiki dress. If I bought it in store, it would be $125 after tax so that's really not too bad.
@FoxC63 - I know you are looking for sizing info. The listing for my tiki dress (size XL) said the following: Armpit to armpit 19.75" with some extra stretch in the cups, Waist 17.75"
I usually wear a size 14 in a dress (sometimes a 12, sometimes a 16 - women's sizing is so inconsistent!) and I figure this should fit me perfectly.