It ain't rocket science.
$1,000 per year?
0.23 per gallon, 25 mpg = $0.0092 per mile for the new tax. So to pay $1k in tax, you'd have to drive 108,696 miles in a year. How many miles you driving? Again, without even accounting for the sales tax cuts, 10,000 miles per year at 25 mpg is $92. Even if the tax triples by 2019, that's $276 per year.
The heirs comment doesn't work either. If you are wealthy enough to die with savings of any kind, then both taxes had the same effect. Both simply reduced the money left over when you die. The effect of the gas tax will be on people who do not make enough to save.
I don't know what you mean by discount it to zero, because if you do that, you'd have to discount the future gas taxes paid too. The important thing is that the numbers aren't even close. People with money are saving big time with the estate and sales tax cuts. 30 years at $276 per year is $8,300. That is less than the estate tax on a taxable estate of $100,000. And that is ignoring 30 years of estate tax savings.