I've been appalled at the price for anything related to weddings, so I bought some cheap flipflops and dressed them up with lace. The cost was $2.50 for flipflops and $1 for 1 yard of lace. Time spent was less than 30 minutes.
Step 1: Materials
Pair of Flipflops in the correct size, thong-style $2.50 at Old Navy
One yard of lace in a pattern you like, $1 from JoAnn fabrics
6 Safety pins
Scalpel or Xacto knife