I'd like to see a nelson based pump, with DETENTS. (One O-ring and one cup seal. Does it get any simpler?)

Well, any pump really. I know some pumps have detents, but that's for stopping double feeding, not rollouts.
And honestly, why can't pumps be under $100.
I love the look and feel of the CCMs but I really don't want to spend $500 for a pump.