I believe Flash Tunes are around $1300 at a couple of sources. That said, the piggyback is 2/3rds that, doesn't involve pulling/installing the ECUs and currently holds the fastest QV 0-60, so depending on what you want out of the car, it's pretty viable and pretty reasonably priced. That said, I think that 10.75 quarter mile QV is a flash.
Odds are, in a few years, more QVs will have been crashed and 2nd hand ECUs should come down in price... and a clone setup may be more viable.
Though it all comes back to the one question I've yet to hear answered. How come the dealer can flash my ECU but no one aftermarket can? I'm pretty sure they didn't pull my ECUs for the last update. I get that there's encryption involved, but when did that stop anyone? Pulling encryption keys out of memory on a running system is borderline common these days. Bribing someone with access to the keys is even more common. But I digress. I think my point was $900 for a piggyback vs. $1300 + time (every time you get a dealer flash update...) is pretty reasonable. All the way up until someone with an ECU flash crushes that 3.49 0-60, and suddenly the "value" for that $1300 flash goes up.
I love the fact that people are pretty exhaustively embracing all the options out there, as it allows the rest of us to make more informed decisions later.