Listen Ruben dude, you are over-reacting. The fact that you are making a mountain out of molehill proves my point, you like to live in a drama.
Anyway, I did not tell you to say "No" to your uncle. I hope you are smart enough to choose your words. A simple explanation about your financial situation to your uncle would have been enough, I think. If he is a reasonable person, he will understand you.
But I see the point, your uncle wants the latest gadget to show off in Nepal, and you want to offer it to him despite your financial situation just to prove that you have the means. Both the characters here want to show-off.
One last point, saying "No" sometimes is not a sign of weakness or rudeness. It is about being assertive. Sometimes it is easier to say "No" and move on than sayin "Yes" and get tangled up with contradictions and obligations.
Anyway, I am done and good luck, you seem to need it.