I love LOVE my Rapidographs. ( If you look on my blog I drew a vintage santa in Rapidographs for Chirstmas)..I started using them in HS for my drafting class ( before Auto Cad LOL) and have loved them ever since. I bought the full set about 5 years ago and have had to replace one nib on a pen ..d/t my own fault. There is a bit of a learning curve with them and I HIGLY recommend watching some videos on how to clean and care for them. I always use the cleaner and cleaning tool for them..and don't have issues with it. I don't have to refil them a whole lot...or at least not enough for me to be aggravated by it. I also love the fact that I can change out the black for sepia ink as well..never used other inks as I have been afraid it would damage the nibs if it dried in the chamber....but in all actuality it would probably be ok..I think I may try it LOL..
I highly recommend them! I *think* Mikes and maybe hobby lobby carry them so you could use a % of coupon to buy them. They are also perfect for filling in some of those finite details that don't always stamp..and for going over certain parts of the image that often get dulled when coloring..I like that.