Currently, we have a data field called EffectiveAmount which shows the current claim bid, including any tips and supports. During a claim takeover bid, the effective amount of the newly bid claim is set to 0 until the takeover completes. If another user tries to take over the vanity URL, they will only be aware of the current vanity claim bid, and not the pending one which could be outbidding theirs. Optimally, we would show the current and any pending claim takeover bids.