Interesting topic , ill put my few cents...
This happened to me several times. Many relatives asking me for phones, tablets, cameras etc. In my case, especially its my little cousins and other small kids. Once I remember, I sent an iphone to my cousin brother (he was around 15 years old that time). I sent him an used but good condition iphone 4 , ( there was already iphone 5 out). So instead of appreciating what he got, he was sad that I sent him an old iphone. If somebody had given me a simple phone when I was in school, that would meant the biggest thing to me). I had my first phone only after my +2.

Going back to the topic:
1. why doesnt your uncle buy it in Nepal itself, if he said he can pay for it. recently you can buy all apple products in Kathmandu, heard theres authentic showroom just opened.
2. Even if you sent it paying thousands of dollar, people in Nepal dont appreciate the value of the product, they think its very cheap here and doesnt realize how much $1700 meant here.
3. if he is planning to gift it to somebody else, then its even worse idea to send it.
4. i personally think that, instead of making other excuses, you should just let him know about your financial situation.