The residence Permit process is rather straight forward and does not assume any investment into an expensive property.
We Register a LLC in Latvia (LLC). Once registered, it will employ you as an employee. With Minimal salary of around 900 euros and the related taxes of around 600 euros per month you will be eligible for renewal without major issues.
After five years in Latvia you may demand the status of the Permanent Resident, that is the Right of Unconditional Stay.
Your Family can apply together with you.