At 4, your child would be too young for this anyway, but you might want to add it to your list of things to see/do in your lifetime. You never know...we didn't have the budget for that kind of thing either 4 or 5 years ago when our kids were that young, but things change.
Chichen Itza was on our "lifetime to-do list" and it was great to check it off. Last year, we flew over an active volcano and that was also on our list. This lifetime list started very small and it just grew. It includes such crazy things as bungee jumping (we did that on my 27th birthday before we "grew up" and had kids of our own), swimming in as many different oceans (Atlantic, Pacific, Indian, etc.) as we can and smaller things like sharing our love of scuba diving with our kids and taking a boatride on The Lady of the Mist in Niagara Falls.
It's all about having dreams, no matter how big or small, and inspiring your kids to aim for the impossible. Think about the list. I promise you that it's quite a legacy to leave your children. Start with one or two things that are doable in the next 2-3 year timeframe based on your budget and go from there.
Cheers!