@SkiMore
It appears to average around 1% per year for most RURAL areas I believe, but it varies in every county. Property tax really isn't something to be that worried about on a sub-$10,000 purchase. Even 3% would only max out at $300 per year, compared to traditional storage costs, way way cheaper.
The land is pretty cheap, anywhere from $2000 to $5,000 if you are just looking for a plot of land without water. I don't know about storage restrictions on the very rural land or if insurance is extra since not in a storage unit (theft/fire/flood/wind), haven't gotten that far yet. You can get small plots even cheaper, as little as $500, but I didn't look at those yet. Most of the rural land has been creeping up in price slowly, so it's not a terrible investment if you find a good plot.
The round-trip gas cost from SE Texas to Central or NW New Mexico is about $1,200 per round trip, maybe more depending on gas prices at the time. However, gas spent is money burnt up, and a plot of land has some resale value if you can find a buyer. You've pretty much paid for the land in two trips, especially considering the wear and tear.
@Everyone else
Most people that are in RV's have children or spouses with them, I don't have the same complications, and I am not bothered by stuff as easily as a wife or kids. As noted earlier, I've been in the backwoods before without water, brought Walmart jugs with me and took a shower outside in a desert that way (very simple). You can just refill a few jugs for showering later at any of the water spots. The water evaporates in 5 minutes, and no-one ever complained.
The less you shower, the safer you are from wild animals :)