Random thoughts on other points raised on this thread:
- Charvet offering Hand details: Nothing breaking with tradition, it was common for French shirt makers to "flat-fell" seams by hand as well as other stitches in the past and there are examples in many design museums. Page Coffin covers this in his book on Shirt making.
- Cost per hand detail: As covered in my post on Neapolitan shirt making, the hand finishes have an incremental cost as those specific job are outsourced to external/home based ricamatrici that charges by shirt/job done. So the standard tariff of approx 25-30 euro cover 8 hand details that probably is a reflection of the amount of labour/hour required per shirt for this. So if you need more hand details, which will take more time, it will cost more and the cost is then passed to the client. IT IS NOT ABOUT CHARGING PER STITCH. Outside the above mentioned 8 steps, additional hand work is normally done on long seams, which will take minutes to be second passed/flat felled by machine but hours if done by hand, that is all.
-Home based (small) and semi industrial operations (large): there are many type of shirt making operation in Naples, some work at home or in small set up with 1 to 3 sewing machine and 1 to 5 people working in them as well larger workshop like Prisco and Lombardi where you may find 10-20 sewing machine and 5 plus seamstress working on them. As far as they still offer a trial-on shirt (muslin) and fitting, all are still bespoke. As explained in my post, at Lombardi they prepare a nice muslin fitting made with very old poplin shirting (the kind you would not want to wear). After the fitting and amendment to the pattern, that muslin shirt became your template which is then sent to the large workshop with your chosen shirting material to be made up. Mr Lombardi does the fitting himself and cut somehow a more comfortable fitting shirt still with proper fitting shoulder, probably more like Ms Matuozzo. In fact some rumours in the city have Lombardi being the supplier of Rubinacci shirt at some point in the past, but bear in mind that his grandfather and father were both already shirt makers with evidence to that on the wall of his studio.
-Unknown operations offering all in one tailoring (Suits and shirt): there are plenty of those in the city, offering all sort of pricing, and indeed they may outsource some of the work to people that also work in factory/large workshop, but bare in mind that this work may be buttonholes, button, lining and probably setting sleeves, these are all secondary operations that will not affect how the jacket fit. I have met a qualified male nurse that does evening home visit for injections etc that works in a very famous sartoria during the morning. The more reliable sartoria (Volpe, Solito, Panico, Pirozzi, Ciardi, Di Domenico, ecc) have all master cutters (which are also the owners) that have trained since they were small childrens under great mastertailors like Schiraldi, Blasi, De Nicola ecc.) That have had great careers and have then set up on their own. With them you will have a direct relationship with the cutter, who would be extremely good in fitting your body as well as have built a reputation as reliable and offering quality, which therefore make them able to ask a price that reflect that but is still not exorbitant.
If this unknown operation offer cut down price, too good to be true, then it is a risk that may not be worth taking. I have had a shirt made up but a similar operation, with a Chiaia location nevertheless, called Le Forbici Partenopee, and it has been one of the worst experiences ever. Looking at the specific link posted by the OP, what makes me wonder is the very cheap price for suit but the relative average price for shirts as well as the fabrics offered, like Canclini having very low entry points and of the suit fabrics, only Loro Piana and Guabello would be worth a look as the others are what Italian RTW uses (most 2x1 low durability fabric).