Ice skating can be fun and affordable, maybe even FREE! As long as you have the proper cold weather gear to be outside, the only other things you need for ice skating are a pair of skates and a place.
Check out area rivers and lakes that are frozen over, they will need at least 6" of ice to skate on. Some communities may maintain ice rinks (man-made or on a river/lake). Your best bet is to call the Park and Recreation Department of the city to ask where ice skating is in the community. Specifically ask if there is a place to skate for free.
We own skates for the kids & I. I bought mine when they were on sale at Fleet Farm, but I picked up ones for the kids at rummage sales during the summer before or at a Thrift Store.
Otherwise, just ask your friends (post on Facebook even) if anyone has skates in the sizes you need. You could borrow from someone or maybe buy. They may sell them to you for a good price or may even just be looking to get rid of them for free.
If a pair of skates are too big by a size, just have your kids put on an extra pair of socks to help fill in the space. With how fast kids grow, chances are they might even fit in the pair perfectly before the season is over.