Hire a specialist who can create custom list based on your specification.
Make sure the list you procure follows the following for best results:

1) You own the rights.

2) vendor can't sell the contacts to anyone else

3) They are all legitimately obtained and comply with CAN-SPAM and GPDR regulations

4) They're relevant to your product/service

Low cost list is a reflection of illegitimate contacts being sold and resold and obtained through illegal practices.

So take help of someone like me :)