Now that
@fohdeesha 's superb work has meant this switch can be
flashed to a Brocade TurboIron-X24 - providing better, more recent software, with full L3 support (except ipv6 routing) and full documentation - this switch is even more of a great deal I reckon.
For those in the UK, I got mine last April for £200 including VAT from
3d-systems.co.uk. That's with dual PSU and rack ears. They show two in stock now, but may have more - I found they often have more than they list online.
They list it for vastly more (£300 + VAT), but my experience has been that they sell much cheaper to home enthusiasts; the list prices are I guess for businesses, or a start point for negotiation!
I was buying a few other things at the same time (an LB4M for £75, two Intel X520-DA1's for £35 each and an X520-DA2 for £75), but I've had decent discounts on all my purchases from them, including the first which was a single item.
I researched used suppliers in the UK quite a bit last year, and never beat them on price. Only when buying from China did I find lower prices.
So I'd highly recommend them for anyone in the UK wanting an LB6M and/or any other used enterprise gear. The guy I dealt with is called Toby Jennings, email of toby@.