I bought a belt and after I crashed it, moved my power system over to the $40 EXI. Flew pretty well like that.
Here's some problems. The gyro on the belt is not great. I crashed my EXI due to the esky gyro going haywire. The servos are pretty slow. For $3.50ea you can get tower pros from Hobbypartz. Well worth it. (get a few extras too!!) My esky 25a ESC caught on fire after 45 flights. I bought an Exceed 40a from Hobbypartz. Lastly, in normal mode, the belt CP is hard to bring down in the wind. You loose too much head speed. One way to overcome this is to run in idle up. After the initial shock of flipping the idle up switch the first time it isn't so bad. You'll notice that the heli is more responsive.
The Pros: For $155 + $40 (or $70 if you get an additional metal head/tail) you get 2 helicopters!!! I'm still using the motor. It's the only remaining part from the Belt. Another plus: I sold all the non-broken parts from the Belt on ebay (including the tx/rx) for $50
Very shortly after I moved over to the EXI, I bought a used DX6i and a AR6110 rx for $150. It was a lot of money, but worth it. If you can't spring for the DX6i, the Exceed 2.4 system that Nuttcaze did a video for is a good alternative, though you can't make changes at the field. Not too big of a deal.... I rarely make major changes once the initial setup and test are done.
Speaking of money, my helicopter fund comes from stuff I trash-pick (or stuff of my own- my wife loves that!!) and sell on craigslist/ebay
If I had it to do over again... I'd go with what Meanbaby recommended:
copterx 450 - all metal - $60http://www.hobbydaddy.com/shop/product_info.php?cPath=150_154&products_id=9070
these are the stuff i have on mines
servos are metal gears, very durable
7.50$ each, get some spares in casehttp://hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=8303
very fast analog, .05 sec!!! and only 12$
esc heres one im using on 1 of my helihttp://hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=6459&Product_Name=Hobbyking_SS_Series_40-50A_ESC
50a esc for under 12$
3700kv, so use 11t for good balance of power and flight time and hs only 16$http://hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=8137
gy400, i have 4 of them and love them 20$ shipped !!!http://www.r2hobbies.com/proddetail.php?prod=rcps61801
Another thing I wish I knew at the beginning was that Finless Bob over at Helifreak has some GREAT setup videos for the trex 450. Not to knock Marc's vids. I love Marc's vids!! Bob goes into more detail about assembling the head. Personally, I like to take things apart and see what makes them 'tick' and to ensure the highest performance possible. If that's not your cup of tea, that's fine. If it is, Finless' videos are worth checking out.http://www.helifreak.com/showthread.php?t=52530http://www.helifreak.com/showthread.php?t=11373&highlight=build