I eventually decided to purchase some secondhand headphones from Ebay purely because of the price difference from that of similar models first hand.
These Sennheisers would have cost me twice as much if I had bought them first hand.
I took a while to pin point just a few makes and models of headphone that I was interested in using online product reviews from a large number of sites and then started to look for these on Ebay.
I eventually chose this model because of the fact that it was pretty much as high quality as I could get without neccessarily needing an external amplifier to boost the signal of the headphones (the audiophile/super headphones will almost definately need this)
I managed to find a legitimate seller with a good rating and picked up these very well looked after headphones.
The headphones are VERY comfortable when worn, I often forget I have them on, the cushioning around the ear can is perfect for almost any sizes of ear and the pressure exerted on your head is just perfect.
The sound is also excellent. I could not believe the diffence in sound when playing my electric piano through these headphones compared to that of a cheaper Sennheiser model. The clarity of the highs and the 'tolling' of the lows was a complete revelation for me when listening to myself play.
This clarity and responsiveness also prevails when listening to music on c.d's.
The bass is very present. My only quible would be that sometimes, with more busy bass heavy tracks, the bass response can be a little boomy at first, your ear will adjust however.
The connectors conneecting the headphones to the cables leading off them also look heavy duty and durable, a plus for me as most of the headphones I have had have suffered because of a loose connection after too much heavy abuse and pulling.
I would thoroughly recommend these. As someone who has usually gone for the lower Sennheiser ranges, the step up has been rewarding. For only £50, if I can look after these and have two (or maybe more!) years hard use out of them I will be very happy and see it as money very well spent.