Will, 101% with you on not paying & just to warn you as you seem to be heading in that direction ... or others might.
The road from Natitingou, Benin to Kara, Togo goes through the Tata Somba region, it's stunning & very interesting. However, there are 'tourist police' just before you get to the end of that road where it re-joins the main road. As a lot of buses come up to show Togo based tourists the sights, they demand a tax. There's a chain across the road.
I was hauled out of the taxi (being the only white one on board but with my 12yr old goddaughter) and taken into their office & demands started at 5,000CFA. I protested saying we were using the road to come from Natitingou to Kande (have i got Kande & Kara muddled up?) and we didn't see much as the taxi didn't stop & I was sleeping anyway. They came down to 1,000CFA each and I still refused. The taxi driver was beeping away in the background & eventually I got away with it. Really didn't expect it & the worry was that we'd not yet been stamped into Togo which we had to do in Kara (the town at the end of the road!)
On the other hand, the police at Porga, Benin as you enter from Burkina must be the nicest I've met in W.Africa, very friendly - took my goddaughter into their box & had photos taken!!!