I think you should try to research upholstery shops first. Some shops can make patterns from your old seats and yes, the cost could be high, but it might be lower than you think. Really good upholstery shops might even repair whats really bad and leave the rest for a very low price. Slightly off topic; a coworker with an old 911 wanted to get the front buckets recovered and new foam. Three upholstery shops quoted $1800 to $2000 (leather seating surface with vinyl everywhere else). I sent the guy to my 'mom and pop' upholstery shop and both seats, with 100% leather, and foam build up was $1000.
After researching many shops in my area (to convert my 2012 Mustang to leather); I discovered there are three types of upholstery shops:
1) Recover only guys: they buy covers and swap. Nothing else. There is not a sewing machine in sight. Ironically, they had the highest price.
2) Super duper premium guys: they buy the finest hides on the planet, do quality work, and for what you get the price is reasonable.
3) Mom and Pop: they do anything you want in the price range you want to pay. They make repairs, foam build up, custom stuff, and have at least two sewing machines humming 10 hours a day. These guys were the most reasonable priced.