You should have avoided Namecheap and their "premium" domains. The "premium" is a made-up term in order to milk customers of their lovely $$$.
They put ad hoc restrictions on selected domains, and these may include unreasonable fees for things like renewals or even transfers to other registrars.
If you bought the domain from another registrar, you would have paid retail price.
Read the comments at https://www.namecheap.com/support/knowledgebase/article.aspx...