Mountain View has an enormous number of vacant recently built homes all because of the slowdown in sales. The island really positioned itself for this problem in part because prices skyrocketed over the past five years to incredible levels. It can be argued that Hawaii has the highest median cost of housing as related to median household income in the entire country. You should also consider that the very low unemployment rate is artificial, in my opinion, with actual unemployment and underemployment serious problems for us. Hilo, one of two major cities here is experiencing a downturn in tourism. If you want to support your ground plants, you will want to supplement it with catchment. Commute times will eventually be an irritant for going to Kona or Hilo for major eating and shopping. But perhaps that distance is what you want.
Ocean View is very local and about an hours drive to either Kona or Hilo and the airports in both. The housing is the most affordable on the island for sure, and there are some really lovely homes there. There are several different subdivisions in Ocean View, some below the highway and one very large one above. Beaches are a short drive and so is Golfing, 2 courses within minutes. Volcano National Park is about a 25 minute drive.
You may want to consider Na'alehu and Waiohinu just a few miles south as well. Discovery Harbour is a wonderful subdivision (I am a homeowner there) built around a Robert Trent Jones Jr. Golf Course with all city amenities built in: water, fire department, electricity, Roadrunner cable tv and high speed internet, paved roads, terrific views, a very active homeowners association. Mark Twain Estates is right across the street from Discovery Harbour, but lacks many of the city amenities. Most homes there do have water and power available though. Those who value their privacy and being a bit more isolated prefer Mark Twain. Lots in these 2 subdivisions run from 1/4 acre to almost 1/2 an acre.
Of course, Hawaii is a special market unlike any other in the United States and I can't stress enough the importance of working with a good REALTOR who knows the area. There are always concerns here that mainlanders don't have: ie: lava zones, tsunami zones, vog, water catchment areas, rainfall amounts, etc.
I would love to be of any assistance if you have any other questions or concerns regarding the Big Island....I know it well!