Since my Raypak is a functional geyser....

[Dr. Spike]

My Raypak is the 'geyser' edition too. The people I bought the house from never drained the heater when winterizing the pool so the manifold cracked.

A local pool builder took a look at it and said the manifold should be <$100.00. It is on back order so I can not confirm the total price or the labor if I have them install it.

You might be able to fix it cheaper then getting a new one depending on what is all wrong with it. I am not sure about the broken studs, but you might be able to replace them too.

[Dr. Spike]

I just did a little search for parts, the part I need is the return header which I found at the price I stated above. If your whole exchanger is shot, that looks like it could cost almost as much as a new heater.