What are a good brand of pens to ink comics with?

Alright, so one of my best friends is a great artist and is really into comics, so I thought a good birthday gift idea would be to buy him some good pens to work with. However, while I’m an artist too, I don’t typically work in ink so I have no idea what kind to get for him. Does anyone have good suggestions? I’m working on about a $30-40 budget. Thanks for the help!