I have been following a few Masters averages because i was curious myself and have never seen anyone post the average for moving up to TM tier. I've seen all the other tier's averages discussed just not this one, which was a lil odd to me.
I always thought it was around 65-66 until very recently, I noticed a master with an average 63.08. And as soon as he hit 63.00 he turned a TM. The amount of ranked games you have is certainly enough, you are just going to have to drop that average quite a bit. = )