SIL's wedding is in August and it's semi-formal. I have nothing formal that fits at all, and I can't find a dress I like.

Problem 1: I gravitate towards dark colors (and it's a summer daytime wedding so I'm trying not to do that) or cream, which I can't wear for obvious reasons.

Problem 2: The family is a teeny bit touchy about me, so I really want to wear something they would consider appropriate. Problem is, I'm not sure what that is exactly.

Problem 3: Everything I like is super expensive.

Help? I need something semi-formal, summery, and reasonably priced.