Hi Susan,
Mickey's Not So Scary Halloween Party is one of my favorite special events at Walt Disney World! You're going to have such a wonderful time!
The exclusive merchandise is really awesome...you can have your purchases sent to the front of the park. It can take up to two hours for the items to get the front for pickup, and there could be a cut off time, so I suggest you do your shopping early on so that you can take advantage of that service.
You are correct, you can also have your items sent to your Disney resort (which is AWESOME, by the way). Keep in mind that delivery time will typically be after 1pm the following day. If you are checking out the day after the party, that's not the best option.
The
Shop Disney Parks mobile app would work really well for you. You can use it on your mobile phone, see what items are around you in the park, purchase it AND have it delivered to your resort room or home WITHOUT having to take time away from the festivities. Having it sent home means not having to worry about carrying them back in your luggage or paying extra fees at the airport.
I hope this information helps Susan. Have a spooktacular time at the party!