I can offer a bit more background on this offer because I've been conversing with Charles for some time. This HE60 has been refurbished last year, but for some reason the transducers that were installed do not seem to be perfectly matching. So if you are a DIYer and have access to a matching pair, my feeling is that you can negotiate an amicable deal with Charles for this package. I have verified his Ebay feedback and he has a very good track record there, even though he's new to Head-Fi.
Worst case scenario: if you buy this and end up having to send it back to Sennheiser Germany for a transducer replacement, it may set you back an additional $800-$900, but then you have the best thing to a new, mint pair and at a very competitive price.
FYI, Sennheiser no longer offers transducers or any other parts for sale. Your only option is to send in these units for service and they perform that in the factory but will keep the old parts. I've been after one of these for a considerable time so these can be a tricky proposition buying used because the transducers and the headpads will eventually require service/replacement.
But when it's all said and done, with the right electrostatic amp (BHSE/ RSA A-10 or a Woo WES) these pack a serious punch. The HEV70 is merely an afterthought, IMHO.
Hope this helps with your sale, Charles. Good luck!