The paint itself isn't terribly expensive. Getting someone else to paint is a bit eye-watering but the overall quality will be miles better and faster than if I did it!
We had one high-end painter (frankly more than we could afford) swear by Cloverdale, but everyone else quoting us loved BM. I can't imagine the Cloverdale guy does a bad job considering the homes he normally works on for decades, but it's what he's used to and the end product turns out well.
My research from years ago is that BM Regel Select is easy to put on, more forgiving, covers well and highly durable. Even the BM store said to stay away from Aura line because it goes on differently (something about no needed backrolling IIRC), so it's tricky for anyone who hasn't used it a lot to put it on well despite it being their most expensive paint. That and it really is only needed for deep colours.
For doors, trim and base we opted for Scuff-X to hopefully help with wear.
Classic Grey and Chantilly Lace.