Many of the horses I've bought have not come with coggins or health papers. Locally, that isn't a problem, I really could care less about either, because really neither is worth the paper it's written on once it's written! The blood can be drawn today & sent away for the coggins test, and two days from now the horse could someone become infected with EIA--so a coggins that is 6, 7, 8 or 10 months, or even 1 month, old really isn't a great guarantee. You know that not so long ago the horse was "clean" but that's the extent of it. But, when we're importing horses from the US, we have to have coggins & health. So, in some cases I've paid for the health papers, in other cases the seller has paid for them.
In the cases where the seller paid for them--and that has been only 2 sellers--they paid for the regular coggins & health paper, and I paid for the extra it cost to have the federal vet sign and seal the papers for export. In one case that was $80 (biggest portion of that is the courier fee to have the papers sent to and from the federal vet via Fed Ex. Some sellers stipulate that they provide coggins/health on animals over a certain value; under that value the buyer has to pay for the paperwork. The last pony I got had a coggins that was 7 months old--1 month over the 6 months allowed for importing into Canada. I had him dropped off at a boarding facility where he had his coggins & health papers all done at once--that time it cost $135 all told. I'm guessing that if he'd needed just ordinary health papers the bill would have been no more than $50--$20 for the coggins and $30 or less for the health paper.