The East Hawaii market is having a lot of activity right now, but most of the properties changing hands are the ones that are priced under the average market price.
While a couple of lots in Mauna Loa have recently sold for around $36,000 the most recent comp is $27,000. Lots in the adjacent neighborhood, Ohia Estates, have recently sold for well under $10,000.
Side by side lots are desirable, however people often want to get an even better price when they buy two lots at a time.
Now is the worst time in years to sell property in Volcano. If you really want to sell and are willing to price your lots low you can definitely move them. If you don't have to sell I would advise hanging on.
I live in Volcano and would be happy to give you any other info you might need about the neighborhood.
I would like to mention that I strongly disagree with the Kona agent who suggested you clear the lots to make them more desirable. Most buyers in the Volcano area highly prize our native rain forest and often will not even consider lots that have been previously cleared.
I believe your lots are part of "old power" which means they already have electricity which can be turned on without paying "SSPP" fees. Water is via individual catchment systems and waste disposal is via septic tank and leach field. I would not recommend any "improvements".