Bids are in increments of $0.5m.
The contract cannot be less than the winning bid. For example, a winning bid of $11.0m can be a 2 year contract of $5.5m, but if a 3 year contract is desired, the amount must be increased to $12.0m, since $11.0m cannot be divided by .05 into equal amounts.
Bids like $5.1m or $3.3m are not valid amounts. Each of these bids would be rounded down to $5.0m and $3.0m.
I apologize for the confusion regarding bids like $3.3m or $5.1. These bids are not valid per se, in that the next bid does not have to exceed such a bid by $0.5m. However, once a bid is made, it cannot be reduced, therefore, if a "winning bid" is $3.3m, that bid cannot be reduced for contractual purposes, because to do so would be awarding a player for less than the amount of the winning bid. Therefore, for the purposes of awarding a contract, the contract amount would have to be increased.
There is an expectation that all GMs are aware of the bidding rules. There is a thread on the Transactions Board entitled "Transactions FYI" and in it, the free agency bidding rules are clearly stated. I accept any criticism for any confusion I may have caused, but in reality, I have repeatedly removed invalid bids and noted the $0.5m increments rule. I guess, in the future, all bids that are not in increments of $0.5m shall be deemed invalid and removed so that there will be no more misunderstandings regarding the bidding rules.