I can give a quote on the sort of roof materials this competes with.

I had to have the tile roof on my 1923 house replaced due to a massive hail storm (in roughly 2006). The house's footprint is about 1000 square feet, so not entirely sure of the actual roof area (probably about 1200 sq/ft), but the bill for removal of the old roof, some repairs to the sheathing, and replacement with new tiles was about $55,000 - materials (Ludowici tiles) and labor.

The solar roof quote for our roof from the Telsa website was about $48,000. So, in my case it would have been competitive.

My new tile roof has a 75 year warranty, btw.

My roof is 1600 sq ft. It had a metal roof on it, which is considered more expensive than asphalt. It was 40 years old, which is the how long metal roofs are expected to last. I replaced it myself for around $2000. Most of the cost was $1600 for the metal roof. Then there was $400 in special nails and trim parts and sealer. It would have cost a little more if it wasn't metal before since I'd have to have added the spacers. Metal and asphalt replacement are sort of DIY possible, but asphalt is dirty heavy work. Metal is less dirty and dangerous, just remember to wear leather gloves. Also probably don't attempt if one's roof has more than a couple gables etc. It's better if you've done it before in any case. To have someone else replace the roof would have cost at least twice as much. Could be three times as much in some parts of the country.

If I were to have switched to slate or terra cotta or glass solar tiles I'd have to tear down the roof and rebuild it because normal houses in the US are not designed to hold that sort of weight, it requires a stronger roof structure, and sometimes stronger walls to hold the heavier roof. Possibly the rest of the structure would have to be reinforced as well. Doing this correctly requires a consultation with a licensed structural engineer. That sort of roof rebuild would cost from $20,000 - $50,000 depending on the scope needed according to the engineer, and that's before adding the roofing materials.

It varies pretty widely based on the material - asphalt shingles are the cheapest of the cheap, and that's what most people would be comparing this to. Tile/slate are much more expensive.

Tesla's initial product is actually intended to compete against premium roofs, not low-end. There are lots of places where you're not even allowed to install a low-end roof due to homeowner association rules.

We just got an estimate for our house (~2400 sq ft single story home) and the estimates were from 10k - 13k.

I had my (very boxy and boring) 1800 sq ft house reroofed with 30 year asphalt shingles for ~$7k, including tearing off both previous layers of shingles.

I looked at getting a metal roof, and standing seam was going to cost about $16k.

Edited to add: The cost of living is cheap where I am.

A 2000 sq ft tile roof would cost about $20k in a large city. The same roof with asphalt shingles would cost about $8000. The warranty difference from 10 to 30 years, the slope and shape of the roof, and local disposal and labor differences will all affect the price.