I wouldn't worry about a thing. Buy the vinegar, use it for salad dressing or whatever and save the bottle. And yes, it's probably cheaper to buy the vinegar in a bottle than to buy bottles froma lab supply house. But mind the caps. Very often these bottles have metal caps and they don't seal very well. If they are lined with plastic and you use it to store stop bath or fixer, you'll probably be ok. Developers are another story. They'll keep much better in smaller, completely full bottles.