Installed 3 skylights in my home during new roof installation 2 years ago. Their price was competitive with other companies I approached, and they turned up on time and did a good job. Neat appearance inside and out, and my lathe & plaster ceiling didn't suffer any damage.
When one skylight leaked earlier this year, they turned up to fix it within hours of my phone call, and it hasn't leaked since.
Would recommend them.

Approximate cost: $1965