Check the backlink profile and if possible check the DA, TF etc. to get an idea. A high PR domain might help at times if you know how to use it. In fact, I have a PR 5 expired domain which I purchased a few months back and is lying unused. I took it to experiment some stuff and will do so when I have some time.
But from a completely non-experimental perspective, PR is not that valuable anymore and quality backlinks are a lot more relevant now.