Curious what you used for maps. I always want to build stuff with maps but the costs can be really high

You can always start with tiles from https://openstreetmap.org Or use one of the commercial providers which offers free tiers. There are quite a few smaller providers that are not super expensive.

You can always setup your own tile server. It's not that hard and can be cheap (if you don't count your time). I recommend, checking https://github.com/onthegomap/planetiler