Buying Advantages on Enhanced Senses

[randian]

Must I take into account the cost of Sense Group modifiers when figuring the cost of advantages on my senses? For example, Discriminatory for the entire Sight Group is 10 points. Infrared Perception is 5 points. If I want to put an advantage on my Infrared Perception, does Infrared Perception have a 5- or 15-point base cost (or even a 10 point base cost, since Discriminatory for a single sense is 5 points) for that purpose?

Conversely, is it correct to assume that individual sense modifiers do increase the base cost of my senses for the purpose of figuring the cost of an advantage?

[Steve Long]

A purchased Sense costs X. If you want to put an Advantage on it, it costs (X x (1 + Advantage value)), just like usual. If the GM has some concern about this, he is of course free to adjust the cost as desired. ;)

However, the guidelines for buying Advantages on Senses on 6E2 14 -- i.e., that characters shouldn't be allowed to do it -- is probably the best way to resolve any difficulties in this situation.