Assuming A and B are students with no income.
A is an avid fan of a rock band, which is coming to town for a one-night-only concert. S/he is really determined to attend this concert and would like to invite his/her best friend B to go together. B is a fan of the band too. A, coming from an affluent family, wants to purchase the most expensive tickets (assume: mosh pit) for the best experience.
On the other hand,
B has been following this rock band with A, and wants to attend the concert too. However s/he is reluctant to buy the mosh pit tickets. S/he understands A’s enthusiasm but does not see the rationale behind paying so much to stand throughout the night. B, from an average family, knows that although the ticket price is affordable, it is an unnecessary splurge s/he would rather avoid.
The core dispute here would be caused by differences in principles and values. A probably did not consider whether it will be affordable for B’s family. B may be feeling guilty to indulge at his/her parents’ expense. And why does B detest the pit?
If I were B, I will try to convince A into the next-best experience-providing tickets which do not involve enclosing sweaty bodies together in a pen. I will want to enjoy the concert too, but how can I do so when I do not appreciate the environment at all? I will still be able to address A’s desire to attend the concert; I only ask him/her to forgo a little from the 'experience' department. Also, overspending on a rock concert is not a wise choice to me. There could be better use for the cash in the family, for example, in extra expenses for the Chinese New Year. Since we are best friends, s/he should understand my position if I explain my concerns clearly.
But if you were A, would you convince me otherwise? (Remember, A is resolute about the mosh pit.)