Its not THAT bad.I don't regret paying $60 for it, even though I don't play it as much as I wish I did. Not because I don't have time, but because its just not fun anymore.
Like I bought it on Launch day, and it actually was really fun for the first like 20 levels in multiplayer when everybody was new and getting the hang of the game. Everybody had a unique loadout and there were new helmets and armor to unlock and look forward to on the horizon. It was a great game, and I barely put it down for like 2 weeks. But then once everybody started figuring out that the DMR was the end-all beat-all gun, it became stale and repetitive like it is now. Nobody has unique loadouts, and 99% of the new helmets and armor are just clutter in my customization screen. Now I barely play it once a month.
tl;dr $40 is probably worth it for the initial experience, sure.
I paid 63$ for it and I still to this day have no regrets. If you like halo and aren't expecting the same multiplayer experience from reach and so on you'll like it. Just be sure to take a break here and there. Mm will get stale if you get stuck playing same modes and maps.