Sometimes they have special rates for AP holders. I just got a room at HRH for December for $139! When I was booking earlier this year for a June trip the AP rates at RPR were only a fraction less of the regular price, maybe $25, still over $200 for the night so I booked at regular rate to get the 2 "free" tickets. I guess it really depends on when you are going what the rates will be. They were running a special through the beginning of June and the rooms would have been in the low to mid 100's but I missed it by a week as it ended June 4, also rates may have been higher for the holiday weekend.
Also the AP gets you food and merchandise discounts, with the room discount combined with what you could save on food etc I think it would be worth the cost, espcially if you plan to eat at the parks and City Walk restaurants. Plus once you have an AP you can renew it for about half price.
I can't tell you how nice it was staying on-site and having FOTL access.