So, being inquisitive and bored, a friend and I decided to see if we can get past the absolutely outrageous price that a McFlurry costs at micca dee's. So, by doing the following, you will get a VERY cheap McFlurry.
1) Ask for 3x30 cent cones to be put into a McFlurry cup
2) Ask for the topping (e.g. m&ms, oreo etc) of your choice
3) Eat your three thirty cent cones with whatever topping in a mcflurry cup :)
Enjoy, this will save you hundreds of percent of the total cost :)
Quick edit - yes topping (e.g. chocolate sauce or fudge) incurred an extra 50 cents.