I had a bad back before pregnancy which then obv didn't help it much, I saw an Osteopath throughout the pregnancy and still do, DD is three now. I Had a C section due to DD being breech - and I have to say the pain was terrible afterwards, I really suffered through having no core strength and having to lay still for so long. I used a tens machine afterwards, which helped, but got blindingly painful back spasms and all sorts of pain at the site of the epidural, even though it was nowhere near the bulging disc I have which has caused the pain in the first place.
However, I was still up and about quickly afterwards, overdid it a bit with the walking, just had to take quite strong painkillers for a while and had some intensive osteopathy to straighten everything out. we are TTC now and it is a worry, but I think I would opt for VBAC only if just to try - but then I didn't enjoy hospital and the whole experience mush anyway, I had wanted to have a waterbirth as the pain was lessened loads in water.
What did help was being as mobile as possible beforehand, antenatal yoga, and now pilates for about the last year or so. I got a good DVD - pilates for mums, that helped as very gentle.
I don't know how much of the pain would have happened anyway - or how much was down to her being breech, as I was very uncomfortable as her head was up in my ribs all the time and was very restricting - it is a tough call but as posters above have said, you just have to weigh it up - and even then, best laid plans and all that....