For some reason, I can't seem to assign a value to some new ingestibles I created for Fallout 3 in the GECK.

First off, in the ingestible window in the GECK, the potion value box is blanked out so I'm not allowed to put a number in. Even when I save the mod and look at it in FO3Edit, the value for each of the ingestibles I created is set to 0, but no matter what I change it to, when I go to a vendor to try and sell these items, they're only worth 0.5 or 1 cap.

What can I do to fix this issue?