I disagree. The only expensive parts listed are the TD/Jesel rockers, BUT! You will get what you pay for and there not that much more expensive than Harland Sharps.
PAC springs are nominal cost, good valves are a must but, a good price is possible considering it is a good investment on the valve & longevity, which are the pay back making them cheap in the long run.
The price of pushrods can vary a lot so I suggest shopping around. There’s no reason to skimp there. Again, like the valves above….