Q: How much work do I need to do for full credit?
A: You must implement all of the listed basic capabilities for full credit.

Q: The spec mentions that "constraint violations or other errors due to data entry errors or bad input values should be managed gracefully." What is meant by "bad input values"?
A: Users that don't exist, bid amounts that aren't numeric, and bids below the current highest price or on closed auctions are examples of bad input values. These bad input values should be disallowed and should not affect continued use of the system.