Not much of a prediction as this has been the case for some time already. Check out prices of used NGVs & bi-fuel vehicles built 10-15 years ago. Also, used CNG tanks are selling for more than the junkyards pay for an entire gasoline powered car. A 10GGE tank with one year left to expiration can cost $450.
there is no hurry to buy as price will come down
Wprt always lowers price as volume goes up
Yes you would buy any time because of savings
And gasoline price vrhicles will be going up as they switch to direct injection