I have a 2003 Saturn and the transmission went out. Will a dealer take it as a trade in? How much?

Yes but you may not like how much credit they will give you for it. Find out how much the car is worth with a good transmission and how much for the repair. Sell the car locally at a reduced rate. It might be 'worth it' to get the tranny fixed then sell it.

To rebuild the tranny will cost you between $1,500 to $2,000 (I am assuming you have an automatic). Dealers will hit you HARD on a trade in not knowing what it will cost to replace it. You will be better off repairing it and driving it or selling it after you repair it. I wouldn't look for a tranny out of a junk yard unless it is LOW milegae.