We too have used wegoshop.com 5 times in the past and been very pleased with their service. Marge is great to work with.
There is no minimum order like at gardengrocer and you can specifiy which store they shop in (including Sam's Club) if you want. I found their site much easier to use than gardengrocer's. The delivery charge in October was $17, I believe. We EASILY saved that over shopping in Disney's stores.
We ordered breakfast things, juices, soda, water, coffee, beer, wine, cheese and crackers and snacks.
As others have said, both services get fully booked for busy times. I usually order at least a month in advance. I schedule delivery for late afternoon on arrival day, and Marge has always been right on time.
Yes alwayslisad, you prepare a list of items you want purchased for you and it can be delivered to you at AK. The cost is the cost of the actual items plus a delivery fee ( and of course a tip).
Have a great trip