Do the math. A windshield is a few hundred bucks and you may go through 1 or 2 over a 10 year span of ownership. Your deductible will usually be too high on comprehensive to cover it so you are out of pocket. Cost difference to drop deductible or add additional windshield coverage costs X a year times number of years. It's probalby cheaper to just be prepared to pay for it a few times. But that's how I deal with almost eveything...insurance isn't worth it most of the time on small things for me.
Let's do the math.
We have to start with a few assumptions:
A new windshield is $700
You need a new windshield every 5 years
A $100 deductible costs less than $50 a year (more than the $1k deductible). Mine is actually $25 a year but that might not be typical
Accordingly, the 5 years of increased premiums are about $250. Add the deductible and your costs for a new windshield are $350
To get back to the original question of protection films.
ClearPlex (Madico), 3M and others make exterior windshield film. Originally developed for helicopters in desert conditions, they've been adapted to car windshields.
Technically, these are illegal in most states but - unless damaged - are unlikely to cause issues. You should figure $500+ for an install with a 3 year warranty against yellowing or damage.