Subtotal does not update if you uncheck the pre-pay buttons
See the attached photo 

I added 2 horses: 1 paid (25$/5 bids) 1 unpaid (0$/3 bids)
Subtotal: Should be 8 bids (it currently says 10) and 25$ (it currently says 50$)
Total: 8 bids (correct) and 25$ (it currently says 50$, which is incorrect)


