Maybe the seller can set how many offers they will allow per ebay ID, but I was always under the impression that ebay set it, not the person selling.

It must be country specific then because ebay US allows 3 best offers. And I sure wasn't allowed to set a number up so it's ebay who sets it.
my problem is that I've seen sellers use a counter offer but can't seem to find that feature in my stores...but still looking...maybe because I got the basic stores feature instead of the super duper one

?
Another possible country specific item - ebay US allows three options for best offers - accept, counteroffer, and decline. And I have basic stores also.
Has anyone tried logging into another country site or the regular ebay.com site to see if it changes based on which country's site you're logged into? I've logged into ebay.uk & ebay.ca when I have issues with ebay.com.