I'm not going to name many names as my largest consulting client is a "local sailmaker". Several comments have been made that are just a bit off as the salesmen don't want you to know some of the secrets of the modern sail business.
First, there are still sailmakers using CAD to design, cut and sew the sails right here in the U.S. They will normally be a couple of hundred dollars more than the overseas guys but if they'll measure the boat and design the airfoil for you, you'll be miles ahead of your neighbor.
You can't make sails from the I,J,P & E of a boat. If someone tells you they can, run! Take a genoa as an example. You need to know the height of the bearing surface of tack attachment from the deck. Full hoist of the track using the halyard car/swivel. Full hoist without the halyard car/swivel (I'll mention more about this in a bit). What's the max leech to the front of the genoa track, the back of the track. How high are the spreaders for the patches (they were included right?), how many spreaders? Do you have a radar on the mast, if so how high and how big of a rub patch do you need. Which way does the drum furl so the UV cover is on the correct side. I hope y'all see my point, and this is only some of the numbers on a genoa. There's an even longer list for a main!
So how do they do it? Simple, they make them too small. Walk down the docks and look up at those headsails. The halyard car should be 4-5" below the doughnut at the top. Due to the perspective of you looking up if you see 5-6" it's really ~18". They'll tell you it's for stretch. Nope. you only need 4-5" for that. But since they didn't measure the boat they just made it small. While you're looking up notice that the halyard car doesn't reach the doughnut to engage the halyard lock, but just the bare halyard extends below the doughnut. Have problems with wrapping your halyard while deploying your sail? Yep, it's too short.
The shop I consult with has been around for 41 years, they are in a small 6000 sqft building housing a sail loft and a large marine canvas shop (one of the largest in the country). The actual sail loft is about 2,700 sqft (and upstairs to not have support poles). In the back is an old Carlson 2 pen plotter/cutter that they use to machine cut the sails from the rolls of fabric. It is a franchise, but not one of the big U.S. ones, but a big one in Europe. They don't advertise nationally but they do have a Distinctive ad in the sailing worlds biker magazine for national outreach. This lets them, like other true local lofts, turn out custom sails designed for your boat and how you sail, not the cookie cutter one size fits all that you can get from a lot of places.
One of the biggest things I've learned about sails is pay VERY close attention to who make the cloth. I've seen brand new rolls at a loft roll out and have bumps and lumps everywhere, but so what cut it and leave 'em in the sail the customer will never know (and if you really don't know what your looking at you'll miss it). Having spent about 20 hours a week for 4 years with them (I do their Accounting / IT / and purchasing), I know this. My boats Dacron or Laminate sails will be made out of Dimension Polyant's materials. Spinnakers out of Bainbridge's Arix.
And I'm not saying that all the outsourcing lofts are bad. Take the Bene 36.7 mentioned above. The Stratis is made in NZ but it was designed by a designer in Fl when that loft was owned by a NYYC member who won the National Championship in his 36.7 and it's a great set of sails. Most racers do tend to flock to the big names, but in the club racing scene and older One Design boats you'll see a lot of the small independent lofts still putting out their custom stuff and it will usually win more than it looses.
I guess I come to look around. If all you can find is a local guy with a sewing machine but doesn't make new ones that's ok, work with him to get repairs / alterations done. Help them find a loft like the one I work with. They will design, cut and assemble a sail(s) for another loft and give him a discount so he can earn some money for his time and effort.
If you don't have anyone local start searching the web for local guys here in the U.S. You've got major concentrations in the Chesapeake, Miami/Ft Lauderdate, Kemah/Seabrook (TX), Chicago, San Diego, San Francisco. You should be able to find a quality loft that will work with you to make sure you actually enjoy buying new sails.
K