hi
this is the true formula for any price.
and selections trigger expression back price is equal or less than ((actual_sp-1)*.50)+1
where the .50 , you can change to any percent.
.50= 50 percent
.10= 10 percent
with all formula you must minus 1, then add 1 after the calculation, because when your selections price is below 2.00 , if you do not minus 1 then plus 1, you will get an error, because 1.96*.50= .98 , so this is below the 1.01 minimum price.
mcbee