Today we implemented a new policy to help cut down on unwanted offers. We can tweak the details, but here is now the system currently works.
When you want to make an offer to a particular seller we look at your offer history over the past 90 days. Specifically, we look at all of your offers that the seller has rejected. Then we look at each item in those rejected offers. We consider a counter offer different from an offer that is explicitly rejected.
If you are about to make a new offer that includes an item that has been in 3 or more rejected offers, we will display 3 strikes just beneath the Remove link for that item, and we will prevent your offer from going through until that item has been removed from the offer. See the picture below for an example.