I want Destiny for that price, but I keep telling myself to wait until the eventual GOTY edition. Sigh..
I doubt they'll do one, looks like their plan is to go straight to Destiny 2 once they're done with expansion packs.
Get the game now, and then decide if you like it enough to spend around another $100+ over the next couple of years in expansions. If not, you'll still get a great FPS for $30.