Players often say that here in the forums, but it turns out to not be true.
A good way to check is to keep track of how many 'hits' you get out of each ball.
The balls I play, 2.5 durability rating, give me about 3, 18 hole rounds (54 holes) at my scoring average of about 60 (1.5 putts per hole) - per ball.
Note too that putts (made on the green) don't decrease ball durability. or put another way, to ensure you get an accurate 'hits' count you have to be aware of what counts as a hit and what doesn't count as a hit.
Oh, note too that it takes 2 parties for a rip off to exist.