Is that necessary from a technological point of view, or is that strictly a business thing that is trying to use the pricing tiers to help with revenue? Seems like a case of artificial scarcity? It seems like limiting the number of items isn't necessary and the costs of maintaining a large database(s) are relatively fixed as you scale up, so why not offer everybody the same amount of items?
I know that a database can only hold so many items, but are there problems with scale where too many items will slow things down? If you only have 500 tenants, that's not a huge issue? The issue is a lot tenants, right? (I guess it matters how you're doing multi-tenancy.) Presumably if you're big enough you can shard and all those tricks that I'm vaguely aware of but never had to deal with.
What am I missing? Note that I've never worked on a large database so I'm quite ignorant — please be gentle!
2) as a company, you also don't want your users to abuse resources and upload unneccessary items to the database, after all, every item costs money (cents add up). This is nothing abnormal -- lots of companies are using a Usage-based pricing model.