Well 715, I am not implying micro incentives like, buy this airplane for 5 dollars so you can be better than everyone else....
Basically you would sign up for the month for $15 to be able to fly the better planes in an arena where everyone gets the same type of planes so that the game is still "fair" if you will. Yet you'd still have the perk system for the temp and f4u4 and 262 ect, so there is still more incentive to play longer in order to get those perk points to fly better planes.
Basically the H2H would be a marketing tool.
Imagine logging on, doing a few warmup rounds in the H2H. Then saying, see you guys later I'm going to MA! People will be intrigued, asking questions about the MA, what's better about it, so on and so forth. So this will also put it in their minds that gee, maybe the $15 for the MA is actually worth it. "I wonder what flying the p51D instead of the B is like. Boom they will sign up so they can try the p51D.
Plus you have the whole ranked aspect of it.
In H2H it won't count kills and deaths like it does in the MA. For many new players rank is something that apeals to them.
So all in all, it's not the pay 2$ for this great upgrade type of incentive. It's pay $15 for the better planes andmore ordendance in a much larger arena with more to do. That way the game is still " fair" for everyone in the MA.