I've used the same fountain pen and Fisher Space Pen for years: I used to constantly lose disposable pens, costing me scads of money every year. The two refillable pens I own now cost enough that I'm always a little paranoid about their whereabouts, so I've yet to lose them. Filling the fountain pen costs pennies. To snag a refill for my Space Pen up in Canada, I can expect to spend around eight bucks, plus shipping. That's 12 different kinds of BS.
Earlier today, I ran across this video. After watching it, I picked up the Zebra refills at Office Depot. It worked!
With my ink budget sorted out, I can spend more money on fancy paper.