Daniel, are the prices you were quoted for a loose plate exchanger or the installed price? If loose those prices sound a bit high. If installed I think the price is still a bit high. Why is it being replaced, leak or fouling? If it's fouled it can be cleaned with a de-limer such as CLR. If that's the case I'd install what's called a Scale Stopper in the cold water line to prevent it from happening again. It's a supply house item, replace the cartridge yearly. If it leaked perhaps you have a water condition that should be addressed.

I was a service tech for 40 years and started servicing EK in the early 90's and loved them. I disagree about steel vs cast iron. I serviced both and replaced as many cast iron as steel due to leaks. As far as "gadgets", the only "gadget" on the EK is the system manager. It's really no different in construction than any other control board on most modern and efficient boilers and furnaces and because EK has a rebuild program that gives a core credit for returned managers, replacement of a failed one is relatively inexpensive.

I like the fact that the manager is not an optional addon, every system has one. Outdoor reset is not necessary and there's nothing to adjust.

If the manager fails and you don't have one just slip in a service board for temporary operation. That's an item available to any service person for about the cost of 2 six packs of beer. It's also one of the best ice sc****rs you can get anywhere.