I have a single speed crankset made by Pro-Wheel. My price is $20 shipped in the 48 US states. Other destinations please inquire within.

The crank arm length is 170mm and it has a 46t chain ring. As you can see it requires a square taper mount. I think the BCD is 130mm. It originally came with my 2006 Downtube 9spd folding bike that I have since upgraded. Pro-Wheel has a website but not all of it comes up in my web browser.
It comes with a double sided plastic bash guard. I put around 1000 miles on the crank set. It’s far from being perfect and new but it’s still in great shape and fully functional. This would be good for a budget build or if you want to experiment with a single speed setup. It has been sitting in my garage doing nothing for the past year and it’s high time for it to find a new home. I cleaned it up as much as I could and prettied it up for you.
My price is $20 shipped in the 48 states. I would be happy to ship anywhere in the world so please ask me what the total will be for your destination. PayPal is preferred. Please feel free to e-mail with any questions.
Thanks!
– Boris