I have a similar philosophy when I travel--camp free (and legally), bathe free, keep costs down and stay out longer.

Whenever I see public land (that's not posted for no camping), I'll stay there. In Indiana, that was on state hunting units, for example--I happened to find those a couple of nights in a row right when I was ready to stop. Ask locals. Some small towns allow camping in their town parks for free or a very nominal fee. Ask at the police station. Some places the campgrounds are geared to RVers and cost over $30 (those are the ones you're noticing). (If the motels in the area are in the $40 range, I'll get a motel then.) Sometimes there's little choice, so my average camping cost is probably in the $5 range. Throw in a motel once in a while (not needed, but I am a middle-aged guy with a credit card, after all) and my average lodging cost long term goes up to near $10/night.

I usually bathe and do laundry in the afternoon on a nice day, sometimes at a town park restroom sink. On a warm day I'll put the clothes back on damp and they're dry in minutes. Many laundromats cost up to US$4 for soap, wash, and dry.

I don't carry rechargeable electronics, but I've seen others use restaurants' outlets when stopping for a meal, some picnic shelters have outlets, and there's always the library.