shimming hydraulic roller lifters solid

It's more than 10 hp.

This is an expensive hobby. $1500 is indeed a lot but prices are up on everything and this is no exception.

Solid rollers allow much more aggressive lobes and more valvetrain stability at higher rpms that hydraulic can't match.
When you understand how a hydraulic lifter actually works, you begin to see just how much variation there can be in lift and duration. They were never, ever, EVER invented for performance. No matter what people say, they are NOT a performance part. If people believe that, they're suckers for good marketing.