Any upgrade requires the corresponding upgrade in valve train components. Heavier weight roller lifters require stronger valve springs = more friction, more power to compress, which in turn requires a better roller lifter to stand the pressure.
More lift requires full roller rocker arms, stouter springs, and better pushrods.
There is a lot of additional expense to cam upgrades, some more, some less. It becomes a snowball.
It's hard to beat an hydraulic roller if done properly.
Flat tappets generally can stand a maximum of 300 lbs. over the nose of the cam if there is going to be any degree of longevity.
Power production is not the only consideration.