(Click to enlarge)

Works for me on the latest v9, see attached screenshot. Are you sure your price field is the only order field you have, and that you're on the latest v9? There have been sorting bugs in the past, and sources/catalogues.php is the main file that needs to be up-to-date.

My best guess is that you're on an older version with a sorting bug that forces it into non-DB sorting, which would likely be doing a string sort rather than an integer sort.

But I checked the code carefully, and I don't think this could happen on the latest code.

(Click to enlarge)

In fact, I seem to still have FTP access to your site, so I'll look directly for you.

Ah, you have the field type as "A brief line of text". So text sort should be expected.

Well yes Chris Graham, what other field should I put there for it to expect numbers? There is no number field - at least one that I could find.

I believe it's labelled 'Integer'. However, you'll need to make it as a new field then delete the old one, as it can't switch underlying database types (it can switch between equivalently-stored types only).

Ah so it is. Float Integer to be precise for my use purposes. Thanks. Assuming that it sorts correctly, this bug is indeed a nonexistant issue.