I agree it would be a good gold sink and like I said, it should only be available very rarely. Like you can only respec once or twice. This would leave room for error while also making people think about what they are doing. Do you agree?
With the concept yes, with the implementation not quite.
I don't think there should be a hard cap on respecs, just a soft one, so that each time you respec it costs more and more eventually costing too much. After time with no respec the price should lower in increments.