A acb is not nearly as expensive as what was quoted above. And DO NOT let the car service fool you the grcery stop IS NOT FREE. It is included because you rent the car by the hour and it is only a 30 minute drive to WDW, thereby leaving a 30 min window of time to go grocery shopping. This is a huge scam that makes the car service rich because everyone pays for one hour and most only use 30 minutes. In essence all trips that go directly to the resort should cost half of what they do, but becaus eall teh car services are greedy they charge a ONE HOUR MINIMUM. Please do not be fooled by these crooks.
The thing that concerns me here is that you do seem to have a vested interest in taxi service in Orlando. The vast majority of your posts are regarding cabs vs towncars...especially as to how car services are ripping guests off.
I do know that a cab ride from YC to Pop is just under $10, and with tip I just hand over a $10 bill. That is one way, for a 5 min ride...very short with maybe a total of three lights....one of which is a right turn, so you don't always have to stop.
If it were me, I would just buy non-perishables at home and have them shipped to the resort..for delivery on your arrival day. Or, use netgrocer.com. They don't offer (at least they didn't when I used them) perishable things, so it might be cheaper to use them and get your milk and such right at the resort. Diapers are a huge issue due to size. they are so bulky that you really don't want them taking up room in a bag unless you are getting that bag free.
If you don't want to do that, just get a car service from MCO. You get the grocery stop. But, as far as letting DME take your bags, you need to know one thing. IF you don't ride that DME bus (at least one person in your group anyway), DME baggage handlers have no idea how many checked bags they are looking for. If you check 5 bags, but the airline misdirects one of them, and you don't use the bus, DME baggage handlers have no idea that one of your bags is missing. So, you get to your resort, get checked in, and when you return to your room, later in the day, you find that 4 out of 5 bags have been delivered. No one has started a search for that missing bag!!! When you ride the bus,you are asked how many bags you have checked. That number is entered into the system, so that the handlers know that they have the correct number of bags for your reservation.
Can you get a car service but let DME handle those bags? Yes, you can. You just need to be aware of the possible ramifications.