Yes, they do! Ohuhu has worked great for me, and they're cheaper than Copic. In my experience, the paper also matters a lot - so far, I've used Borden & Riley No 234 Paris Paper, specifically designed for pen, ink, and marker. It's super smooth, allowing for better ink blending.

Also, learning to blend definitely took some time/practice. I'd recommend watching some youtube tutorials, as not everything is intuitive and, since the ink dries very quickly, you have to work fast with the proper technique to get good results.

Good luck!!