Where the game stood in comparison to its competition, let's say, the early 2000's, is quite different from where it stands now. It's basically the same game, albeit with GV combat, ship-to-ship combat, amphibious landings with battleship support, etc.
Then, it was an up-and-comer, drawing players from Warbirds, AW, Fighter Ace, etc. The first to offer flat-rate pricing, IIRC. Now, it's the Gray Lady (I mean that affectionately) of multiplayer WWII online combat, competing against War Thunder, DCS, IL-2 Great Battles. The best thing about the game is really the community and the fun we have when we're online together.
I'd be afraid a price hike would cause too many players to re-evaluate whether the game is worth the price, compared to the free online play and continuing development and new releases by its competitors. We might lose more players than we can spare.
It's not really about whether Hitech deserves a raise - its about what the game offers in the current environment against it's competition, and what that is worth to new and existing customers...