If he is handy and doesn't keep a cordless drill with is RV stuff, you can get a decent Black and Decker one for around $50.
If he likes music, how about some CD"S with his favorite music.
Maybe a lawn/beach chair.
If he frequents places where there are mosquitoes get him a Thermacell and an extra box of Butane and the blue pads. The two together with tax will be a little under fifty.
We have given those lots of times for gifts
jack L