Moot of the turkey fryers are only big enough fir a 10-12 pound dressed weight bird. The pot might not be big enough.
I use the burner part of the turkey fryer and I purchased a galvanized wash tub to hold the water and do the scalding. That is big enough to scald a large turkey or a goose. The turkey fryer burner does a good job of heating the water. I think the galvanized tub was $26.
I own several large stock pots and tamale pots and none of them are really big enough for scalding. You need to get the bird into the water and squish it around. It's difficult to do that swishing in a tall narrow pot.
The wash tub can also be used for large parties. You fill it with ice, sodas and beer. So, you can get a little more use out of it than just scalding turkeys. Of course, once you own the wash tub, you are obligated to be the one to give the large 4th of July and Super Bowl parties. So that is an additional expense.