pedals
I'm sure somebody else has done this before, but I should mention it if people don't know. I own a USB logitech steering wheel with pedals, the "wingman" model. I've seen them for sale for under $50 used. The pedals work perfectly for helis in all sims I've played. The pedals need to plug in to the steering wheel, but I just stick the wheel away somewhere under my desk.
The only real downside is that they are obviously smaller than real pedals, and not linked with one another in a true rudder configuration. But both pedals are spring-loaded, and return to a "center" position on their own, so they may as well be linked. For a cheap rudder control substitute, it's great, and works perfectly with Black Shark, and helis in FS too.