Decent price for Halo on PC.
Halo, Halo 2, Halo 3, Halo 4, Halo Reach - $10 each. Halo ODST - $5. Same price on both MS Store and Steam.
So works out at $55 for the lot, which is ok. But it's nice that they're reasonably priced separately if there's any you don't want. I.E if you only want to play 3 or Reach you can pay $10 instead of full price for ones you don't want. And of course they'll all be included with gamepass.