sure, not uncommon to hear people doing this. Just keep in mind any discounts on food, purchases and free parking will require you to be there to show you have an ap and may require you being the one to pay (some cms are sticklers on the who actually hands them a credit card, uses the band to pay or hands cash). If your a family that splits up, consider what the lost discounts might be and if that's enough money to get someone in each "group" an ap.
Some of the discount appear online but there is also ticketless discounts that do not. The only way to find out all the discounts is to spend time on the phone with disney. note you can also book an AP rate without having the AP yet if your planning to upgrade tickets when you get there. I've been told you had to upgrade within 24 hours of checkin or you'd be charged the full price of hte room automatically but recently some people posted that they had to upgrade before checkin so i'm not sure what the current policy is, the person on the phone should know.
side note, this might be a good time to consider a
travel agent where you pay disney direct. They can take the account and help you work up best discount based on ap or not (if they are good).. wouldn't cost you any more money if it's a good
travel agency that specializes in disney.