Bulk updating items ALREADY in a collection

Not totally clear what you are trying to describe.
Please provide an example-DATABASE, with some more details.

  1. Bulk-Updating is possible…
    https://www.wix.com/velo/reference/wix-data/bulkupdate

  2. If you know that your database will grow later, you could just prepare more free columns inside of your database.

I think your problem will be, that you are trying to genereate new columns inside of the database dynamically?

New colums will be generated automatically if you change DB-IDs inside of your code.

For example you have at the beginning just one DB-FIELD (column) called —> “title”
Now you need another (further) column inside of your DB.

A new DB-Column will be created after a SAVE-PROCESS…using…

update()
insert()
…or …
save()

or going the bulk-mode…
https://www.wix.com/velo/reference/wix-data/bulkupdate
https://www.wix.com/velo/reference/wix-data/bulksave
https://www.wix.com/velo/reference/wix-data/bulkinsert

After a successful insertion/saving/updating, you will get a new generated column inside of your databse.

Is there any way I can do this without essentially adding another column and typing them all in?

Why would be wrong going this way?
Having just one DATABASE —> less query-loadings → less waste of loading times → faster WEBSITE ?

Should I instead make a seperate prices collection with a reference field to location?
Possible, but like already mentioned above - → more time-consuming.
2-DATABASES = 2-query-processes

1-DATABASE = 1-query-process.

Yes the DATABASE gets bigger, but you have everything inside one DB.