1. Bowling-we used to go to our local Brunswick on Sundays when everyone else went. Games are $1.29/each before noon. The place is always packed. Recently we discovered that the place is pretty empty on Sat. a.m. and since I get coupons from Brunswick for weekend games for $1.49 each, DD11 and I can both bowl for less than $10 and since I finally bought her some bowling shoes (craigslist) I no longer pay the almost $5 for shoe rental. I still use my own shoes from 25+ years ago.
2. Movies-AMC theaters offer first run movies for $6 before noon. We saw African Cats last Sat. (only paid $5 for some reason?). Movie cost the 2 of us $10, popcorn was $6.50 (a splurge), bring in our own candy and drink waters. So we both saw the movie on opening weekend for under $17. Oh, and since I buy the large popcorn, I refill it before we leave and use it to make the easiest, and really good, caramel corn. We take that to DD's softball games.
3. Beach-Pack a lunch. Parking and gas less than $20. Lifetime of memories=priceless!

My DD11 loves the beach and if we take a friend for her to play with, so much the better!
4. Picnic lunch-again pack a lunch, bring things to play with.