I do video editing every so often and it takes for ever to render a video because I like maximum quality. I'm thinking about getting a cheap workstation card in the $100 range. Would it be worth it to get a card this cheap? Do any of you have experience with cheap workstation cards?
You'll be locked to the CPU performance most of the time anyway, an inexpensive card would only really be able to help while previewing effects. Save up for a CPU upgrade if your current one is not too fast.
OpenCL accelerated video encoding could take off in the near future, or may even be worthwhile already with some of the very latest versions of some video editor. But it would take a more powerful card to really make a difference still. Unfortunately a lot of hardware accelerated video encoding is focused on low to medium quality video, and some like Intel's quicksync are hard locked into that area. So such solutions would not be for you, or me.