It can be pretty comical (and impressive) to see what kind of clothes you can get at a thrift store for $5. Pick out outfits for each other (or for yourself) using no more than a pre-set budget ($5 is plenty), then wear the outfits to do one of the other date ideas (bowling, ice skating, etc)
They have these all of the time too, if you’re watching for them. Just wander around and ask car owners about their ride — they get all excited and love to tell you. Then if you’re not really impressed, you can go away and make fun of them!