How expensive is it and where is it offered?
It has been a few years since I patronized that service. This was at least 7 years ago, at the beginnng of the digital image explosion.
It was not cheap, but at the time the images I had to deal with were priceless. I am sure the cost has come down by a factor of at least 5.
The specific service I used was The Darkroom, in San Rafael, California.
Any image over 5 mb can produce a paper print as big as you'll ever need. Any good Lab can transform the electronic images to 6x6 negatives or positives. Let us know if you can find current prices. 7 years ago it was about $8 an image, if I remember correctly.