crf50f, second hand 1000, new 1500-2000. 108 big bore (1K beats all those 127cc) mini tapers 50, Swing arm 350 Suspenction front and back $700. And there is not much more that you need + it will be quallity and won't break. All comes upto around 3500. Also you can do those other little upgrades and things and there is a wide range of parts for the crf50. They are also significantly better for stunting and they will go hard. I say fark chinese and go jap if you got a big budget. Also use ebay if you can and try get the parts cheeper would be good advise.
The mojo bikes as far as i see are brillient. They have great forks front and also the back spring is good from the reviews i have read. They all come with good bars (another+) They look good and they claim there frame is good wich paying 3400 i supose it is. The other pit bikes are out of the question. "pay 900 and mod the hell outa it with 2500" thats just stupid. You got the genuine deal here and won't need to do a thing. Good bikes these. And also what i like is there is more range than the thumpstars. BUT the other thing i would consider is the TERRAMOTO bikes will be out soon. They have the ttr-90 style grapics by the looks of them. They have a brillient engine (same as the mojo) But they also have the same forks at mojo (mazorochi or whatever they called) they have got the best looking swing arm and a good frame design. I think the stock back shock is good also. But i wouldnt think it is as good as the mojo ones. As far as looks its personall oppinion. I love the style of the terra moto (thumpstar) new look. Bloody great i think. But then other people think they look bad. I think the mojos look sweet but then again they have crf50 plastics and will look like all other knockoffs.
OVERALL:
I say get a crf50 and mod it. OR my seccond oppinion would be wait a month if you can hold on and check out the terra moto range. But if you can't the mojo expert is a great bike. I rode a new one and they are better than the 05 thumpstars. I havent riden a 06 one though. So yeh man just out of those three> CRF50 and MOD it, TERRA-MOTO,MOJO
also what i didn't mention was the 06 thumpstars, i think they are basically the same as the 05 ones, becides swing arm and a few other little things. Goodluck man hope this helped.