To go hand-in-hand with the soaps, you can buy very inexpensive, plain hand towels or wash clothes and sew a strip of lace along the edges. It makes the towels or wash clothes look more expensive and sort of Victorian. Also a couple of scented votive candles are inexpensive and they can be wrapped and tied in a piece of fabric as sachets. I did a hub on the sachets for a kid's craft project.
Sounds like a fun auction. Another gift basket idea if you have any DVD's that are in new shape - you can do a basket called "date night." Add a couple of DVD's, pretty paper napkins, a couple of candles and a package or one serving of microwave popcorn.