few ways to get to Tibet
1. you can tak an organise tour from Katmandu, but you get permition for short period, and you spent a lot of time, just in the roads... anyway, after this trip, you can stay in Tibet, as long as your Visa is valid (if you're issue it in Nepal is for 30 days). 2. you can go to chengdu in Sichuan province, and take a flight. it cost 2,000 Yuan, only the flight and the permition... 3. go to north west of China, and have a tripby buses from there... 4. and I think also from Deqin, in Yunan province. anyway, for my opinion, there many tibetian towns in mainland china. I heard (haven't been in tibet) that Lahsa is full with chinise, and anyway, you spen a lot of money there, comparing to rest of west China.