Using "Individually per selection" in User variables

I want to record the back_price of all market selections in some user variables at various times beore the off.
How would I then refer to the back prices recorded in a subsequent backing trigger?
If I simply use Selections back price is less than MyselsT1
                  and selections back-price is less thant MyselsT2
                  etc...
Nothing seems to happen.I need the back trigger to compare the current price at say 10 secs before the off with all the individual back_prices already recorded in previous user variables.

Any simple solution or will it take a trigger request?

Seasons greetings
In the screenshot 1st column is recorded price at 8 mins 2nd column is recorded at 4 mins. At 10 secs before the off trigger backs all selections whose back price is less than the two recorded back prices. You can add more triggers to record prices when you want then just add the conditions in the backing trigger. 

Thanks Mark I'll probably give this a try on Boxing Day with all those race meetings.  Merry Christmas to you and yours.
There is a commercial bot that runs this strategy very well, but I don't need all the functions that offers, so I was keen to set it up on MFPro which is cheaper anyway.