I live in a 1930s home in East Texas. We have some doors that need to be replaced: three sets of French doors that are 48" x 91" (each set) and two doors to exterior closets that are 30" x 80". So nonstandard size - I understand that. The quote we received for fabrication and installation was $28k. Reasonable or no?

Yikes. Call Detering in Houston. Won't be cheap, but probably not as bad as your other quote.

www.detering.com

Are you asking the carpenter to match a specific detail and profile from other doors? If so, that might be a reasonable price. The carpenter will have to buy custom shaper profiles that he'll never use again. If you're just looking for a shaker door or 6-light, then no that is not reasonable

Could also get a quote from vintagedoors.com They make custom sizes. The French doors from there will prolly be in the $2k-$2500 range (assuming you want glass)

Thank you very much for the suggestions!

Custom details for the French doors - but the exterior closet doors, no! Will follow up on both suggestions.

Ouch - obviously get more quotes, but yeah non call sized doors and a problem in terms of cost not matter how you slice it.

Could be worse. Last year, I had a guy tell me that a standard-sized, no frills 36" fiberglass front door with no sidelites was going to cost me $8,000.

Seems to calculate out to be $225/sf for the whole tamale

A fancy Home Depot std.size door is ~$30/sf, assuming an EZ install @ double that.
Most std.size doors are cut shorter to suit by-the-hour, even hollow core types.

Some build "to order" but in a factory ala Simpson https://www.simpsondoor.com/how-to-order/
Also Andersen .... and local door companies - if they cater to non-builders

If looking for craftsmen, many appear with their door-art at festivals e.g. Renaissance Faires or
Home & Garden Shows.

Lastly, there may be a LOT of labor that may go into fixing even the door frames in a 30s house, etc. etc.
If all options are blocked, you might feel better if the quote was more detailed as to where the money goes and if not forthcoming, then another quote that will itemize might better serve.