I think it really depends on how it all balances out. But I think a good thing worth watching in regards to MicroTransactions and how they (should) work.
Basically, the idea is to set the In Game Currency(IGC) so that you can still get all teh stuff you want with grinding, but at the same time setting the Real Money Transactions(RMTs) low enough that people will realize that their time is worth more than the cost of the RTMs, and once they make the first purchase, they'll be far more open to making further purchases,
A Good analagy is Steam, think back to your first Steam Purchase, then think back to how often you made the following purchases, ESPECIALLY
during the fantastic Steam/Christmas/whatever Sales.
Frankly, this talk of 40-60 dollar mechs really scares me, because frankly, that reminds all too much of the "Make teh most money out of the fewest people" schemes, when really it's been proven(based on teh already mentioned Steam Sales) that teh Devs that take part in them still reap huge profits despite teh greatly reduced prices. It makes so much more sence to me to make RTMs as comforatble and open as possible, because once they start rolling then tend not to stop.
And Don't See the P2W thing being an issue, so long as everything regarding the actual game play(mechs, weapons ect ect) can also be purchased with IGC, they iut just has to back back to showing the player that their time is more valuable then the cost of the RMTs.