sometimes these things just happen,
I've know this sort of thing happen in many places - for example, in London girls may have different prices on different agencies/websites (some varying by £100's) and in Holland upselling can be pretty common (€50 basic but the the bra stays on!
)
not sure how old/new database entries are but maybe a recent change? possibly a mistake?
Theres so many elements involved. As Jordanc said, its not worth arguing over such a small amount.