Features of this sort exist, mostly, to push the boundaries of the extremes. It can buy you some f-stops and/or shutter speed clicks. When shooting in bright daylight that may be a marginal improvement, but in lower light, it can be critical. Sometimes it'll be the difference between a shot that looks fine on a web page but can't be enlarged to a gallery-quality print. Maybe exhibition-quality is an important consideration, maybe not.
I own three tripods, of varying weights. When I'm out hiking all day, I'd prefer to carry the lighter tripod. Since OIS adds little or nothing to the weight in my pack... One thing is certain; for the kind of things I shoot, I can't go anywhere without a tripod - OIS just changes the threshold at which a tripod becomes essential to the shot.
But in the end, "if a tree falls in the forest..." We adapt our technique to the limitations of our hardware. If I don't have a long lens in my kit, I may have to crop/enlarge to an unacceptable degree. If I don't have a sufficiently wide lens, some shots become impossible. If the lens is too slow, subject motion may be unacceptable... So we shoot what is practical, rather than waste time on shots that simply won't work out. That can be a very useful discipline, if we choose to be inspired to overcome those limitations, rather than be stymied by them.
When I was much younger, I might show someone an almost-successful shot and say, "If only I had... this would have been great." Now, I don't show anything for which I'd have to make excuses. So, how much is "the one that got away," worth to you?
I'd add that you need to invest where it'll do the most good. If that $100 buys you another bit of useful gear... If you had no tripod at all, I'd say "tripod rather than OIS."
