Out here, a flowerhorn comparable to yours would go for $50. Considering where you bought yours (at a lfs), retailers have overhead expenses so it's understandable why they charge more. If you're ever in the market for another, search for one in the marketplace of this site, aquabid, facebook...even craigslist have some really nice ones from time to time.
For the time being, enjoy what you have and flowerhorns definitely blossom with age.