You can usually tell the folks who are sincerely curious from the ones who are trying to either A) imply you are a spendthrift, or B) snoop into your finances.
When someone is curious I'll let them know that it varies by your travel style and tastes, and if they would like me to send them some tips I'd be happy to, I also make it a point that they need to be aware that getting maximum value for your travel dollar means spending a lot of time and effort on due diligence up-front. If you are not willing to put that effort in, it will be more expensive.
As for the other folks, I tend to match snark with snark. I always like to ask how they afford the vehicle they are driving, or the house they are living in, or their NASCAR habit.
FWIW, I find that people tend to fall into one of two categories when it comes to discretionary spending: there are those of us who value STUFF, and those of us who value EXPERIENCES.
(There are also those who value mind-altering substances, but that's kind of a separate subcategory,

) I find that the people who tend to snark about what I spend on travel (not just theme park travel) are people who tend to drive expensive cars, live in large homes, re-do their kitchens every 5 years, carry iPhones, and wear only name-brand apparel -- in other words, people who value STUFF. From that POV, spending a large sum of money on travel is a total waste, because when the trip is over, what you paid for is gone.
BTW, for the PP who mentioned horses: the answer is, a not inconsiderable amount of money, especially if you don't live on a plot of land large enough to accommodate them. Even if you get the horse itself for free (which is fairly common in horsey circles, due to the practice of trading foals for boarding), there is the cost of feeding them, and the frequent bills from the vet and the farrier, not to mention the cost of things like tack, utilities and maintenance for the barn.. Keeping them at home in a rural area normally costs a bit over $100/mo per animal for routine feeding and care. The expense easily doubles if you have to board the animal at a facility any distance from your home., or if you show the horse. Of course, as with travel, there are ways to reduce the cost, such as learning to do your own routine hoof-trims.