Waterman Serenity $9.99
I enjoy Lamy Blue. It is a beautiful royal blue. It isn't expensive and the bottle comes with a free roll of blotter paper! In my experience, it plays well with all pens and flows freely without being overly wet.
How about Akkerman Shocking Blue?
You can get Akkerman inks over there?? Wow!
I currently have a ... Kaweco Classic Sport.
I have been using only the ink cartridges exclusively. I tried ordering a kawecoconverter but it is currently out of stock.