Here's one you won't find very day. In fact, you can look, but you may have trouble finding one at all!
Nakaya Naka ai is in Ama Iro, a sky blue finish that was discontinued some time ago and has become hard to find. Best of all, the pen is equipped with Nakaya's rhodium plated 14K gold Music nib, a nib that at least here in the US has been on backorder and is therefore not currently available from the sole US dealer.
The Naka ai measures approximately 150 mm long capped and 138 mm long uncapped. The pen is cartridge converter filled and writes wet and broad, as can be seen in the writing sample below.
The pen has been lightly used and is accompanied by boxes, kimono, and cartridges.
$995 includes shipping within US.