The first rememberizer is available for a steep price just after recruiting Kyle. Considering there are 3 Bromides available as well most players will miss out on this one. Don't worry you have more chances to pick up this item which is used to view the cutscenes, including a chance to get a free one.

When you accomplish your childhood dream of becoming a dragon master make sure to stop by Remus's shop and talk to him. This will get you a free Rememberizer at no cost (and is the original way of getting it on the psx)

If you miss your chance at getting the free rememberizer for whatever reason, there is apparently still a chance to get one in the epilogue, although since I grabbed mine and am still going through the game I can't verify this. From what I heard you will have to pay for this one though (gotta support Remus's shop if you forgot to be a bro earlier after all)