If i recall correctly, CGA doesn't apply, but as a result of negative press on this exact thing, some retailers will have a policy on the matter.
Supercheap Auto for one actually proactively credits you the difference if an item you purchased goes on sale shortly after.
They definitely can't hike up the price and then claim it's "on sale" back down to the pre-hike price, but that's the closest thing it covers.
__________________
ɹǝʌo sᴉ ǝɯɐƃ ʎɥʇ
|