Design, cut, make, pack and distribute in the shortest time with minimal investment what is called Fast Fashion today has neglected custom-made clothes and today buying a garment (of doubtful quality) can be cheaper than a meter of good quality fabric.
The cost of a custom and personalized garment requires the work of a professional, tailor, dressmaker or seamstress in addition to all the materials, machinery and expenses associated with the manufacturing process, so it is expected not to be a cheap service.
It also influences the cost of making clothes the quality of service, the popularity of the professional and even the location of the sewing establishment, atelier or clothing workshop.
Regarding the quality of the fabrics, two criteria affect the final price of the garment: that the client supplies their own fabrics or that the sewing professional supplies them. This usually occurs more frequently in tailoring and haute couture atelier that have inventories of high quality and special fabrics for haute couture suits or dresses. The type of fabric, sewing very fine silks, güipur, velvets entails a degree of difficulty superior to what it would be to sew cotton fabrics.
Regarding body shape there is a difficulty of making garments of very large sizes, since these require some experience in handling the patterns that only trained or experienced professionals have. At the same time very large sizes will require an extra in fabrics and materials. And although it seems strange the same happens with excessively thin or very small people.
The degree of design difficulty is another fundamental factor when calculating how much a dressmaker, seamstress or tailor costs. Some very complex designs require the preparation of a test model with several tests until reaching the perfect measurements and then go on the definitive fabric.
So defining a standard price on how much the sewing service costs will not be possible.
Certainly around the planet there are excellent sewing professionals as well as not so professional, so depending on what you can or are willing to pay for a dressmaker or tailor service you will have to be careful when choosing one. But if you have invested a certain amount of money in fabrics and materials you will undoubtedly have to look for the best tailor or dressmaker.