Did the Brothers Regret Selling Joseph?

One of the most spellbinding questions in the give and take between Reuven, Judah, and the other brothers is whether they actually felt bad about having sold Joseph?

Is there any indication whatsoever, at any point, that they felt that they had done the wrong thing?

I think that the simple answer is "No." 

And, were they to have had to have made the choice, they would have done it again. And that, is a sadder reality than almost anything else - which is why, when Yaakov passes, the brothers come to Joseph and say that their father had instructed them to cajole Joseph into forgiving them on his behalf. 

It is an anti-climax of the greatest proportions; essentially, they themselves have never reached closure amongst themselves, which hearkens back to the earlier question, "Why was it that they sold Joseph?"

Having seen him as a mortal threat - feeling that they would be evolutionarily disposed of as were Yishmael and Eisav - they felt that he, Joseph, the manipulative, underhanded and sole progenitor of the Jewish people needed to be eliminated. 

But, they did not hear him crying out, begging for his life. That is the only expression of remorse that we see. Upon being accused of spying for an enemy country, that is the only admission they make: This was God's will because we saw our tormented brother, and we shouldn't have calloused our hearts to such an extent; it should have awoken something within us, so we could reassess, hear his side, and re-thing the reality. 

That undertone is expressed twice when Joseph finally reveals himself to his brothers. Twice he says things that show that he had special faculties that they were not aware of - for indeed, a brother dreaming that his siblings are to be indentured slaves, who bow down to him, does not make for brotherly love, to say the least, and indeed does pose a mortal threat. But, when Joseph finally does reveal himself to his brothers, twice he says that there have been two years without plowing and harvesting, and there are five years to come. Essentially, Joseph is saying I had special prophetic qualities, those of a dreamer, perhaps innate like those granted to Bilaam, and you were not aware of that, but when I cried out and begged for your mercy, perhaps you should have re-assessed, you shouldn't have closed your hearts to a point where you could not hear another's cries, those of your own brother. 

There is a powerful scene in "Schindler' List," where a Gestapo official is about to shoot a Jewish prisoner dead like a dog, and Oskar, says, "You could easily shoot him dead, you have every right to do so, and that's what anyone else in your place would do, but to show that you're truly in control is to go against what you would otherwise do. To show that you don't have to shoot him dead." It's a remarkable scene that pulls on the official's heartchords, not because of his humanity, but because of his perverse understanding that he could become even greater by wielding power in a different way. If the Gestapo official could do that, the same was expected of Joseph's brothers. Did they ever make the realization that they had done wrong? Perhaps not, but having closed off their emotional faculties, by refusing to listen, they prevented themselves from using their intellectual faculties, and acumen, to wonder, to dream, whether life could be different than it seemed at first glance.