Subscription based model is such a horrible and outdated idea. There is a reason why every new subscription based MMO keeps failing (most recent example is BioWare's Star Wars: The Old Republic).
IMO, the only viable option for such a niche market game is a free-to-play content-based model. You pay for what you want when you want. Both DCS and RoF are already on this train.
__________________
Windows 7 64-bit | AMD Phenom II X4 3.4 GHz | GeForce GTX 460 1Gb | 8 GB RAM | SSD | Track IR 5
|