The TWSBI Diamond 530 is a very high quality Taiwanese-made pen, with outstanding features, at the incredible price of only $40 + about $3 shipping. It was created from long brainstorming sessions on the fountainpennetwork forums. The guy behind the pen (forum name Speedy) is very involved in the pen's development and the customer service and tech support he offers is outstanding, by all accounts.
I can't wait to get mine. Unfortunately I've run out of inks to put in this pen so I am also placing an order for some additional inks and hopefully I will get them in time
to try out on the TWSBI.