I'd pay $100 a month in a second. $200 for heated and enclosed. I can't build and heat a building big enough for my camper for near $200 even in 30 years of payments.
Cinderblock advice about the holes being vertical is good advice as they are designed for maximum strength when placed that direction, but there are load ratings for the blocks both ways....and generally, when split 6 ways...plus 4 jacks...you won't come close to the limit of a cinder block, no matter which way you put them.
As far as your advice about not parking in your driveway due to the way it looks...and your neighbors....I couldn't care less. My property, my right to store what I want. Of course, I don't get along well with HOA's...in fact, I'd never consider buying a place with one. I also could never live in a subdivision with houses so close together. I can't stand other people telling me what to do with my property.
I think most truck campers are people who are independent. We get truck campers because we enjoy doing things outside the campground....not surrounded by the masses.