Not sure how much you are looking to buy but...we looked into it and well the cost for the service is at leat $17 plus tip for any order up to $100...and the fee increases if you spend more...we are going to be there from August 4th through August 20th so we did a bunch of research to figure out the cheapest way to get stuff...and here is what we came up with...
We are shipping via FedEx most of our non-perishable item (ie. ones we can get cheaper here at home in bulk) like swim diapers, diapers, wipes, sunscreen, individually packed snacks from Sam's, etc. directly to the hotel so it will be there for us when we check-in..sending on Monday and we arrive on Friday ...we are shipping about 50 lbs worth of stuff and it is going to cost us about $17 to ship...with the savings in diapers alone that I can get here vs. there, the shipping was paid for and all the other stuff we threw in was a bonus...
Because we are going to be there in August when it is HOT and drinking water is a must...we order cases of water from Staples...they deliver directly to the hotel in one business day and if you sign up for their free rewards program shipping is FREE...so we are ordering a few cases staggered throughout our trip there for $5.89 a case/24 16.9 oz bottles...we freeze some and then refrigerate some and in the AM when we leave for the park we take a few cold ones and a few frozen ones...
Then regarding perishable items like milk, bread, fresh baked snacks, lunch meat, soda and yes beer for the adults...we priced out the delivery services versus renting a car for a day from Alamo...in the end we are renting a car from Alamo from their Walt Disney World Dolphin location for a 24 hour period and getting a compact car and the total cost with tax and all is only $18.99 (13.99/per day)...the trick is the 24 hour period has to be Sunday pickup though Thursday pickup...not only is it the same price as if your order is $100 or less...but cheaper if $100 or more plus we can pick what we want while we are at the store and we have a car to go to the Nike Outlet with now...which is worth the trip if you have a car to go to...
Just our experience and plans...we have been going to Disney now for over 20 years for at least 2 weeks a year or more and this is the best plan we have come up with yet
Good luck!!
