Yes that's correct about the cloning.According to this list, the Joyo AC Tone is a clone of the Tech21 SansAmp Liverpool. I haven't heard either, but the Tech21 pedal does come in the same conversations of good Vox in a Box pedals that mentioned the Catalinbread ones.
I mentioned this in another thread, but I owned the SansAmp Blonde and the Joyo American Sound at the same time and the Joyo sounded great. The Tech-21 was around 300AUD at the time (they're now discontinued).
I'm sure the quality of the components would be night & day, and the two main differences that I know of were the footswitch was a soft touch and the V2.0 had a a switchable speaker emulation. The Joyo speaker sims are fixed.
As for cost of building vs buying, that difference is impressive, and great incentive!
The few times I've priced out parts for pedals (with only mere contemplation of building) it's not been as economical as your numbers. However that was not any bulk buying, just one-of prices. Not to mention my circuitry knowledge is weak beyond pickups & pots!