May already be done, may not have been. I wrote a small program in VB. Its an Ah calculator where you input what you want to receive for an item you sell and the program calculates backwards to what you have to post it on AH for to get the price you want.
The way it normally works:
Armor posted to sell at 200g.
Deposit of 1g25s34c
AH fee is 5%.
Result you get 200g - 5% + the deposit. which lets say you end up with 193g56s45c.
Three text boxes, 1st is input for the amount you want to end up with after fees. 2nd box is the AH cut which is 5%. 3rd box is the deposit.
Enter the three numbers, click calculate the number that appears is what you need to post the armor for on Ah to actually receive 200g exactly.
By the way, you'd have to post the armor for 210g25s95c using the 1g25s34c as a deposit.