It's a good buy at that price. Length is a concern, but it's not too much shorter than Prime (if you know what you're doing in Prime. I remember my very first runthrough of Prime was 32 hours, but i get it down to 8 routinely, 9.5 if i go out of my way to 100% it), and my first runthrough of Other M was about 10 before the post-game (which iirc added up to about 14 hours at 100%, though part of that involved me getting stuck in long one-way passages), and i think that didn't include all the game-overs (which are a lot easier to get in terms of ambush and similar scenarios)
It's shortness is overestimated, especially compared to Fusion, where 4 hours was the beginning qualifying time for better endings (that is to say, the least of the rewards you had to come in under 4 hours for)
Monster Hunter: pissing me off since 2010.
