Model S base prices: 60 is $66K, 75 is $74.5K, 90D is $89.5K. AWD on 70 or 75 is $5K, new autopilot is $5K. Other options you may want will total $5-10K. Yes it's expensive but see what you'll be paying after you're done with a Mercedes or BMW option list.
The federal tax credit is $7,500. California rebate is $2,500 but now has an income cap of $160K. The rationale of these policies is that new tech is expensive but get it going and the price will come down. In the case of Tesla, Model 3 reflects the mid-priced model enabled by sales of the early adopter cars. And as I noted early in this thread the federal tax credit is phased out after a manufacturer has sold 200,000 cars in the US.
That's the theory, but we can question that most Model S/X sales might have occurred anyway without a subsidy. In the case of the solar roof panels I installed in 2009 the California early adopter subsidy was very lavish and the panels would not have been economic without them. Since then prices have halved and efficiency increased 50% so solar panels in CA are a better deal now than then even though the state rebates are long since gone.
While I've taken advantage of these programs, that doesn't mean I think they are the best public policy. There have been failures like Solyndra, and the California rebate for fuel cell cars is larger than for battery electrics. I think those will also turn out to be a complete waste.
All industries curry favors from the government if they can, and in the case of Florida the utilities have totally blocked the rooftop solar industry, which could benefit many people there.
The best answer to pollution externalities from an economic point of view is a revenue neutral carbon tax. I-732 was such a measure proposed on the Washington State ballot last week with reductions in sales and business taxes (WA has no state income tax). It was defeated by an unholy alliance of fossil fuel industry and some environmental groups (including Sierra Club) that wanted to spend any new revenue on their pet programs. I agree with the characterization of such groups as "watermelons:" green on the outside and red on the inside.