Oy! Scratch that...I saw HD and thought hard disk when it comes to me now that you probably mean High Density! I have an external HD 3.5" floppy drive branded "Power Computing" if that's any help. As for cost, I got mine free. Well...on on "extended loan" TBH. I also once heard that Dell sold an external HD floppy drive for Amigas. That could be false, tho.