Vendor FastPay Issue

I have set up some vendors using a freebie, Ettavend Multi Vendor. It functions ok, but the issue is when Pay is selected from the pie menu there are multiple price buttons and a field to enter price in the FastPay menu . I would like to have only a single button with the price of the item. I was hoping to be able to edit some parameters in the script to accomplish this. After searching this forum, I found references to llSetPayPrice and llFastPay but the vendor script does not contain either of those functions.
Does anyone know an easy fix for this? I am just a novice scripter and I hope I dont sound too dumb...

This would have one button for 50L.

llSetPayPrice(PAY_HIDE, [50, PAY_HIDE, PAY_HIDE, PAY_HIDE]);

Thanks, that worked.