Once upon a time there has been a "black list" of a German forum (not on WUS):
Jacques Cantani watches are very similar to AK, Rene Barton, Steinhausen, Aeromatic1912, Tauchmeister watches, mostly housing chinese movements and claiming to be "Made in Germany" (Read my post
https://www.watchuseek.com/showthread.php?t=1396 "Do you remember" here on the German Watches Forum).
Some watches are utilising swiss movements.
Mostly no reliable after sales service and nobody to talk or to mail to. Some customers complained problems in ordering spare parts.
Some movements and cases are - maybe - made by "millionsmart" or another chinese company.
Similar "brands" (just some):
Adee Kaye
Astroavia
Bernadino
Cavadini
Centia
Charles Delon
Claude Valentini
Denacci
Eric Edelhausen
Ernest Rochet
Jeane Melaine
Jean Jacot
Krug Baümen
Leutwyler & Söhne
Louis Valentino
Maria Giesen
Montres Allison
Newton & sons
Nomex
Olivier Witteaux
Oskar Emil
Ottimo
Raschke Glashütte
René Barton
Roebelin & Graef
Röthlin
Rudolph Rüttli
Tom Tuder
Steinhausen
Wilhelm Rühling
Vidar
Reason for that blacklist was: All watches have in common that you hardly get´em at a retailers shop (there are exceptions !!) but only on the internet (mostly: ebay). Most of them pretent to be high quality watches. Jacques Cantani watches are titled "Meisterwerke der Uhrmacherkunst" - Masterpieces of watchmaking" - but closer inspection proves they are not.
Other sellers on ebay sell top offers, dreamwatches, extremly rare

-D) JCs.
According to offers I read some of these JC retail for 1200 Euro. Another fairy tale.
I usually call them "ebay-pop up-mushroom-brands" because they pop up like mushrooms.
But if you fell in love with a JC go for it. But keep in mind that JC isn´t a "real" german brand. You´ll get what you paid for. 50 to 80 Euro seems appropriate.