01/2010 for entire new unit - US$ 69 at The Binnacle, US$70 at Defender, US$ 86 at Fisheries Supply, US$ 100 at West Marine
When assembling in the door, one can chose which side has the knob and which side the lever. One can also chose which side has the latch which "locks" the handle for privacy.
If one wants a complete unit with levers on both sides (thus no knob) it takes several days for Perko to special assemble and ship one to your "dealer of choice".
If one wants to replace an existing knob, one can special order a lever through a dealer. There is no Perko part number and it takes a little extra effort.
If one prefers knobs to levers, the reverse of all the foregoing is also possible.