small code update, on Data sheet FD2 replace the formula with this.

=IF(FC2="","",IF(1/FC2*MainSheet!$R$11>100,100,1/FC2*MainSheet!$R$11))

Then copy down, this will put a max price of $100

As seen in Doomben race 2 if you had 8 runners selected the bottom runner was $100 but the 7th selection was over $380, makes no sense with the prices like that but the rating order was correct.