I had a 5th gen Accord and got mine replaced for 195, including parts, tax, and labor. It came out great, and I've had zero problems with it since. I don't think it would be really worth it to do it yourself, unless you've got some sort of experience that I don't know about. With stuff like that, DIY isn't always a good thing. Any small screwup and you'll have a leak, or something.