Buying tefillin?

Hey everyone! I’m using my throwaway so my bf won’t see this.

My boyfriend’s birthday is coming up, and I want to surprise him with tefillin. The problem is that I would like to buy them online and make sure they are kosher. Additionally, I’m looking for some that won’t break the bank. We are modern orthodox.

My question: does anyone know a trustworthy place to buy high-quality, kosher tefillin online?

Thanks!