My SO has been telling me for a year that I needed to buy waterproof hiking type sandals for the parks because he loved his so much (he has ones that are called Rock Rivers that we bought at Modells a year ago and they are still going strong despite him wearing them constantly). I, never wanting to admit he might be right, insisted that I needed to get sneakers with strong arch support and into which I could put gel insoles.
However, the new sneakers I bought before my trip caused bad blisters on my heels, and I relented and tried to find sandals before I flew down to Orlando. Couldn't find any hiking type sandals anywhere and I live in New York City where I thought I could find anything on sale at the last minute. So, I figured I'd try and find them in Orlando (but I still was convinced they would not provide me with the same comfort and support as good sneakers).
Long story short (too late!) once we got down there, we drove past a Nike Outlet on 192, somewhere before Marker 8 I think (not sure, could have been a much lower Market number). The prices on sneakers and sandals were FABULOUS and the selection was terrific! I bought a pair of sandals for $30 (and they had much cheaper ones, just didn't have my size), put them on, and I was transported!
I put up with my boyfriend gloating and "I told you so"ing because these sandals are an absolute dream. I've never been able to get through a day at the parks without back pain and foot fatigue and aching calves. But these sandals, despite the fact that they look like they don't have much in terms of arch support, are miracle shoes.
Not to mention that they are they only way to go when doing the water rides at Disney/IOA/Sea World etc. No more saturated socks and sneakers!
I now have traditional footwear to go with my traditional theme park outfit!
My suggestion is you can always wait till you get to Orlando and hit the outlets!