which sim for my tx and interface?
That value equation only works if you are going to give up flying real models and just play with the sim INSTEAD. I tend to look at it as either I can buy 2 or 3 kits and use a free sim or I can waste all that kit money on an expensive sim.
Just different points of view. I find FMS great for having fun and I don't really like RF G2. For serious practise I still use CSM v10 which has a superb flight model but seriously ugly and old-fashioned graphics and sound. Still available and about 1/3rd the price of G2 (over here at least).
Steve