Not op, but ours is a Lelit Elizabeth dual boiler. Not cheap but I expect it to last like our Gaggia Espresso Deluxe did, about 15 years. I could’ve gotten away with a single boiler, truth be told but the ability to preinfuse (in a somewhat proper way) depends on it. Non negotiable was the PID temp control. Timed shots is nice to have.
But really I could’ve spent more on the grinder and less on the machine. The grinder I first got wasn’t up to the task of espresso. Didn’t have the range of settings and the grind quality was subpar. Had to get one a year later (grr) and settled on the Eureka Mignon Silencio. The flavor profile is so much clearer (this was obvious from the first shot I made with it) due to grind quality and it has stepless adjustment. So I can dial in the shot pretty well. Timed grind is nice too.
But damn what a lot of money for all this. Still worth it. It’s not much over 10-15 y. And it pays for itself quickly. I can have an espresso drink every day that is far better than many places offer and it costs significantly less even for the super expensive, fancy beans.