I started out buying just parts and used broken tanks of all sizes and scales just so I could get some hands on and learn. I've fixed up a bunch, mostly just replacing old NiMH batteries but I've fixed gear boxes changed out electronics, etc. As of now I've got a couple of Konami DigiQ, a bunch of the original VS-Tanks, a VS-X Set with a T34 and a Tiger, a 1/24 VS-Tank Pro Sherman, a Taigen 1\16 M41 Walker Bulldog. Have a WPL and a JJRC truck in that mix too.
I just recently bought my first new tank, a plastic Heng Long M4A3 Sherman that I've just begun to customize into an M4A1(76)W HVSS. I'm also playing with a couple of other projects mixing and matching parts from different R/C tanks and Toys and after years of reading modelers' posts in the "Show Off" forum and thinking how cool his stuff was I'm finally doing my first 1/35 conversion on a Tamiya M41 Walker Bulldog. Not partial to it, just that found 3 for $11.00 each at Hobby Lobby so guinea pigs. Nothing to shout about just yet, just a lower hull and suspension running around on a $6 toy controller and receiver.
In a year and a half or so I've gone from zero to my wife's comments "You have a tank problem" when she comes into my office in the basement, little does she now, I've just gotten started.

Thanks!
Ziptar (Kevin)