It used to be that if you wanted a great pen or pencil, something with some heft to it but also something durable with a very clean design, but you did not want to spend a lot than the Rotring 600 was a great choice. If you were a bit more picky than you could opt for one of the original models (with the knurled grip). If you were a bit more picky than you could upgrade to the gold series. If you were a real Rotring connoisseur you got yourself a gold series with the the twist action. These twist (retractable) models have always been hard to find, but lately the prices have been insane. Check out this eBay auction- $219 for the pen! At retail this pen was probably no more than $50 (just a guess) but now they appear on eBay a few times a year and always go for over $175. The same goes for the less desirable pencil...