POWER what can I get for $400

I am in the process of nearly doubling the size of my layout and am in need of more power. I want to continue with track power but would like to be able to run more than one train remotely. I like the idea of a wireless transmitter so I can follow the train around and flip switches when needed. I have looked into the aristocraft train engineer (not the basic since that only runs one engine)and I like it, it seems simple and easy to use. Question is who makes the best system for minimum funds. The biggest bang for the buck. Whichever one I get I would like to be able to build on the system without having to junk it and start over because it is lacking something. I don't see myself ever powering switches, signals, lights or sounds in the near future so I don't need that ability plus that seems like it can get confusing quick. I am looking for something relatively basic to run more than one train at a time. I read some postings here and checked out Tonys' train exchange site. That sight has a lot of info but I would like to know what the experienced RR man is using and why.
DCC DCS and all that = Don't know?
I do know that each engine will need a decoder to be wired in but 27 mghz or higher and more money for each one ?? Where does it all start and where does it end??
A starter setup would be nice what do you guys use and what would you recomend for me and my budget of up to $400. I currently run 2 LGBs'from starter sets and a Bachmann big hauler (non annie) and will have near 300' of track when done. Do I need 10 amps? I like short little steam engines that will haul 1-6 cars around but I do have some grade issues of 2-2.5 %
I am posting this same query to the beginers forum since that is what I am when it comes to this kind of RR stough.
I hope my needs are clear enough. Thanks alot for your input.
Todd