My suggestion is to file a ticket about it. The admins might be able to view your shop history to see if it was actually priced at 510K rather than 5mil.
Did you use an autopricer after pricing the lily? It's possible someone else priced theirs wrong and when you used the autopricer it set yours to the lowest price which was 510,000 instead of 5,100,000.
[flower=RedSekhmet]
Probably you didn't count right, or you deleted a zero before clicking.