The flaw in the question asked is that you can only pick one, when in reality you might be able to buy 2. Or you could buy and play one for a few years and then sell it to buy the other. Either way this is a good battle and votes are now 93-94 close.
As for availability, it is way easier to find a MM or MMr to buy. Which is why I am puzzled when a nice LOTR shows up and it takes 2 or 3 months to sell. It should be more like a day to a week. The demand for LOTR should far outstrip supply, making it hot, hot, hot.