An example of an ONIX file: https://www.pug.fr/product/9782706147951/onix

Thanks Adam for your quick response & continued committment to Zotero.

My question is most probably very minoritary : after having used Zotero for years for research purposes, I am now trying to use it for commercial purposes: i.e., I'm opening up a bookshop & for the time being, I don't want to pay expensive bookshops' softwares. I may try to use Abelujo, a free software dedicated to bookshops, but didn't yet manage to install it (it runs only on Linux, and I only recently managed to install Linux).

The added value, for me, would be to automatically include a resume of the book (which ISBN doesn't always do), useful when managing a bookshop. I would also appreciate if it could automatically include the prices, with & without taxes, but as Zotero doesn't have a field for price data, I suppose this is impossible.

Currently, I manually insert prices in the "authorization field", and use the "cote" field (just above "authorization") to put the code-name of the distributor to whom I have to command the book (bookshops don't contract directly to editors but to their distributors, for instance 3012600500000 SODIS refers to the book's ID for command to SODIS distributor). By doing a quick search with "SODIS", or putting them in a "SODIS folder", I can then easily prepare my commands to SODIS. I can also transfer the files to OpenOffice Calc, thus having a column with prices which allows me to do the accounting.

It is indeed strange that the place of publication is not included, but is this always the case? French ONIX files have a field refering to the BNF (Bibliothèque Nationale de France, equivalent of US Library of Congress), which displays, for instance, http://catalogue.bnf.fr/ark:/12148/cb445178914. This ID does include the publication place, and the ISBN (as you can see following the link).

I wouldn't bother Zotero with that if I could find another way, but I have less than 2 weeks to prepare my orders for at least 3 000 books (at term, I will have around 5 000 books in my bookshop).

ERRATUM: 3012600500000 SODIS DOES NOT refers to the book's ID for command to SODIS but only to SODIS in general.

ISBN tries to get data from BnF and where that exists it's great, but it looks like BnF is surprisingly selective in which ISBNs it finds (looks like maybe only one ISBN for any book, so e.g. not the paperback ISBN if they have the hardcover). If the data come from Worldcat, they are indeed not great.

I guess what I'd say is that it's a fair amount of work, but manageable for a develope -- you're likely looking at 3-5hs dev work, so maybe 500-600US$ if you want to try to find someone to code that in a rush. Or you could see if @AbeJellinek who works on translators for Zotero full time considers this high enough priority to put it on his list.

No, we wouldn't look up additional data as part of an XML import; Zotero would just import what's in the XML, hence no publisher location(s).
The commercial info also doesn't have corresponding Zotero fields, so much of it wouldn't be saved in a useful/structured way.