I asked them to split the difference, and they came back with 55K, a 2K increase over the original offer.
I was thankfully able to get my current employer to give me a raise that has brought me up to what I think my skill set is worth, so I'll be sticking with my current job for now.
Didn't you try to counter their offer again. Like "my current employer has offered me more to stay, if you could make the 70k then we could still be on?"