We have ressies at T-Rex and Rainforest Cafe. I have noticed when looking over the menus that you can add a salad for $xx.xx at these and other TS.

My question is this: If I am on the DDP and ask to substitute salad for the fries/chips rather than add them as a side, will I be charged extra for that being that I am substituting and not adding? I have diabetes and it is noted on all my ressies - I can't do fries or chips. I know Disney's policy is to "accommodate special dietary needs", but I've never asked to substitute anything before. Will they take that into consideration or will they charge me anyway?

TIA