Shoes (or lack there of...)

I am having the hardest time finding some summer shoes for Rachael!! Not only does she have monster huge feet for a 20 month old, they're currently at the in-between stages of 7-8. I know, I know, shouldn't that mean 7 1/2? Of course it should, however, basically the only store who makes toddler 7 1/2 is Payless. I'll get to why I can't get her shoes there in a minute. Being at this in-between stage, Rachael's feet are too long and barely fit into a 7, but her ankles are too skinney to fit into an 8, they just flop right off. Lame. Finally I just broke down and got her a cute little pair of brown sandals from Target the other day, size 7. They have on strap across just below her toes, a strap that wraps around her ankle and velcroes on the side of her ankle. They worked well, at least for now, minus her toes would slide and hang out a lot of the time. Come to find out in the tub later that night (P.S. Kids feet get a LOT dirtier when they're wearing sandals... FYI) that she had this horrible looking red welt on her little ankle from where the strap dug in. She hadn't been complaining about it all day, poor kid, but I wouldn't want that. This specific style of sandal is basically the only one out there (hence no Payless). And I swear to you I've been in literally every store in this town that sells children's shoes, even some in Phoenix this weekend, and I cannot find her a single pair of sandals. I usually like to spend $15 MAX on shoes for her, and that's if she is going to get a lot of wear out of them, but at this point I'd be willing to dish out $30 if I could just find a pair. Any suggestions? Any of you have shoes your daughters have outgrown and you would be willing to part with?