Torque Converter Replacement

[juiceman]

What would be a normal cost to replace a torque converter on my 93 J30t

I have been having some shimmy/hesitation and whne I dropped the pan there were flakes in the pan and sludge in the pan. Cleaned it and took it to a local shop (500miles later) and there were more flakes and the magnet had more on it. I thought the TC was going when it stumbled a few times when warm

Thanks for any input