I have a site that lists several items per page. When the user clicks he can see each item's prices (a list of about 10-20). They are not visible at first because the page will be very long.
I want to tag them with the schema.org/offer microdata structure. How can I make this tagging seo friendly? Is it only possible if each product has its own page? Items are dynamic and change every week that's why I figured its not good to have a dedicated page for each (and also for user experience).
It’s perfectly fine to describe multiple entities on the same page with Schema.org.
However, depending on what for your favorite consumer (e.g., a search engine) would like to use your markup (e.g., enhancing the display of your result in their SERP), it might be that they only show this enhanced result for an entity’s dedicated page (which you don’t have).
For example, Google Search’s Product Rich Snippet wouldn’t make sense for a page that lists several products, because the Rich Snippet refers to a single product, its rating, its price etc.:
That’s why Google Search requires a "a product page" (or "a shopping aggregator page") that "describes a single product" (bold emphasis mine).
Anyway, if you don’t want to provide dedicated pages, having Schema.org markup on the listing page is better than not having Schema.org at all. It just might be that you would get no SEO benefit out of it (unless there’s a search engine that works with such listings; maybe in the future).
