Quartzsite has some very low cost RV parks just under $200 per month. But electricity is never incliuded and sometimes there is a sewer and water fee as well. Still they are a good bargain. If you have solar for the majority of electric use it is doable on a modest income.
I spent the winter at La Posa South which is very close to town. There are also other LTVA sections even closer to town that are walking distance. The whole of the season from mid October through mid April cost $180. That includes garbage, water andd sewer dump. You can stay there in an SUV but must camp somewhat close to one of the vault toilet buildings. It is a great bargain pricewise and there is lots of community friendship available if you like that. But it is easiest to do if you setup for solar power. You can get cell signals there, stronger the closer you camp to town.