My estimation based on fur prices would be that you'd need to pass over around 6-8 hides to get one tanned for you. Since you're in Misery (intentional misspell), then I'll expect fur prices are in the $15-20 for you this year for GOOD coyotes, the same as they are on our side. In general, it costs somewhere between $75-100 to get a hide tanned. So if your taxidermist gives you full market price for them, you'd be looking somewhere in that 6-8 hides ballpark to make up his time and cost, at least.
Now, does your taxidermist NEED 6-8 coyotes, or even have use for them? Probably not. And if you ONLY SHOOT 6-8, then you most likely don't have 6-8 coyotes that your taxidermist would want to buy, since they'd be looking for the best of the best. I can't say that any of the taxidermists that I use would need so many. Unless they regularly buy green pelts and regularly sell finished hides, then you're probably handing them a lot of work and a lot of hustling.
Keep in mind, that a great number of taxidermists don't tan their own hides, so they send that out. One of the guys I've had do coyotes for me in the past charged $75 and he said he had $50 each at the tannery to have them done, so the only money he made was for the fleshing and stretching. So if you're passing 6-8 coyotes to your taxidermist, you're really passing him a bill for $300-400. If I'm a taxidermist (and I've tanned enough coyotes into saleable wall-hangers to qualify on this front), then I'm not interested in that trade. Maybe you'll get lucky though.
I'd say that your best move is to find a trapper or better still, a fur-buyer, sell what you shoot, but keep the best of the best, then use the buyer payout to pay your taxidermist.
And of course, the reality of knocking down 6-8 coyotes on your first outing in one weekend is highly unlikely. You'll have more cost in gas driving back and forth and in putting up the first few hides while you're trying to fill your limit than you'd spend in paying the taxidermist to do that one hide for you.