Minimum acceptable price
A minimum acceptable price is the worst price at which a stated recommendation still stands.
In plain English
It turns a recommendation into a conditional one. Above that price the reasoning holds; below it the recommendation has expired, whatever the opinion about the game.
Example
An instruction reads: back this side at -3 or better, down to a price of -120. At -135 the instruction no longer applies.
Why it matters
Without a stated floor, a recommendation is unfalsifiable, because any bad result can be blamed on the reader having taken a worse number.
How V8 uses this term
V8 instructions are price-conditional and state their terms, so a reader can verify the conditions were met rather than trusting a bare selection.