A new sprocket assembly will certainly not give you a new life expectancy but if you do it yourself it will be about $40.00. The part number is 41C4220A and it comes with instructions. One big plus for having it replaced by a professional is that they will check your door. A lot of times it is a neglected door that causes the gear to fail. I don't know where you live but $350.00 for a 1/3 horse opener is a little on the steep side. I would call around.

We need to replace the Genie chain-drive door opener in our garage.

My question is, do we have to replace it with another chain-drive opener, or could we get a different type?

I realize this may be a stupid question, but I don't really know much about garage doors and openers

Any type you like will work just fine.

Thanks don!