Cobhall common is in Allensmore, right?
At that distance I would expect that to be the case.
I am only going to get 33Mb, and I live about 700m from my cab - VDSL doesn't stretch as far as you might think.
So you're best bet is either Allpay or wait for the government funding thing to kick in about 2015. I remember reading about the different phases of it but I can't remember all the details now.
http://www.meetinsight.org/
Try that link and see what you find from there.