Let your parents pay for this one, but mentally plan to pick up the tab for a nice evening out for their 30th in 5 years. Idk how old you or your parents are, but you have a brother in college so I'm assuming they're not 70. If that's the case, while we never know what will happen, I think waiting until their 30th and planning a lavish night with the whole family for that would be great. Assuming, of course, that they aren't going to take themselves on a big vacation for it or something. But then you could do it at a different time anyway. In 5 years all of the brothers will most likely be on more stable financial footing, and possibly split the bill. Or you'll have this money set aside in your head for 5 years, so even a $2,000 meal wouldn't bother you. I say let them pay tonight, take a nice gift and enjoy time with each other.