there are cheaper sims. I've been using Realflight G3.5, but I'm trying to get an adapter/drivers for FMS which is free http://n.ethz.ch/student/mmoeller/fms/index_e.html , Clearview is very inexpensive: http://www.tucows.com/preview/419730 . That said, what I've read I'd gather Phoenix is the highest rated sim. The sim will allow you to get the hang of things, then work on specific skills well into advanced flying. I started without one, I'm really glad I have one now.

after that, iI'd suggest saving some coin and going for something used. I don't care if you want to try some cheap and cheesy coax dual rotor, a hot trex 450 or a larger 600mm size nitro. If you start with a used machine it may cut your costs in half. If you don't like, turn around and sell it. You'll mostly likely get close to what you paid. I've even seen used deals that include the sim. Just be sure to tear it down and look for issues before you fly.

You have nitro cars, haven't said if you are more interested in electric or nitro. I'd say a nitro heli is easier to tune than a hot 1/8th scale. Boats are pretty bad ass too, but again it depends on what you want. You can drop $1200 into a basic gas boat that would be fun, but you could do a nitro heli for that too.