While contemplating do some rerolls I always like to look at value per roll. Lets assume that odds are terrible and you really only pull 84s.
11 rerolls is 30800. 11 84s get you a 90. At 4 to 5 TP ratio you are paying 123k to 154k for every 90 you make. So you pay double for each 90. So making a 94 will run you anywhere from 861k to 1.078 mil.
Now lets say you do 12 rerolls and can acutally pull a 90.
12 rerolls is 33,600. 11 84 get you another 90 so you end up with 2 90s. At 4 to 5 TP ratio you are paying 134k to 168k which is a little more in line to what you would pay to buy the 90s off the AH. So making a 94 will run you anywhere from 469k to 588 which is close to market price.
So then the question becomes can you pull more that one 90 every 12 rolls? If not you lose. If you can you are even. If you think you can get 2 90s every 12 pulls you are well ahead. Anyone who is at home try rerolls with any luck?