Its not your fault. You are simply following the market and market has a habit of adapting the grapevine technique and word of mouth without experiencing on their own. The most difficult yet fruitful results come from personal experience.
If you are seriously considering for getting a cuore with low milage and guaranteed outclass one of a kind condition for 7lack then please let me know.
btw why do you want to run it on cng when its already giving a good average??