I think about the best money can buy in tap wrenches is Moore and wright. The older ones like so many things are nearly always the better ones. Even with company's like eclipse and Moore and wright they still go to the far east to get the majority of their stuff made these days.
There are a lot out there on the market often the cheap ones are just that, cheap and often horrible to use. Horses for courses as usual, if you will be clearing out half a dozen threads per year for your car or something anything will probably do you. If you are trying to produce half decent threads, something nice to work with is always a bonus.
Try eBay as suggested, Cromwell tools or J and L industrial. You will get a half decent usable quality from the latter two.