Prusa constantly updates their stuff and it is often pushing the limits of the hardware. This has made every cut price clone obsolete by the time they come to market. This is a moving target. That is the business strategy to avoid clones trying to undercut Prusa. The clones also have no resale value just like all of the mass produced junk and even more so for proprietary. You actually own a Prusa, even the right to buy or sell it second hand. You own it for life and no one can take that away. It is the lowest depreciating option you will find. From that perspective, it is the cheapest option you can buy.
Marlin, RepRap, and Klipper are just baselines. If you're doing one yourself Klipper is the only way that makes sense. It is a ton of work. This is like saying "I have a broken down Mercedes and I can get a Chevy 350 crate engine for $1500. The amount of time and effort in between those two are far more than anyone realizes without experience. The results speak for themselves when you look at how many people have prusas and actually use them to print things that are not printer hacks.