e-flite apprentice

Does anyone know what motor would work for the apprentice that wont cost $70? My brother in law has one and is in search of a more economical replacement motor.

Hey everyone, I am Silvester, I'm 15 years old and I live in the Netherlands. I recently ( about 2 months ago) bought a HobbyZone Super Cub S RTF, and I have become addicted to flying it since then. I fly as much as I can, but there is a lot of windy, wet and cold weather (It's winter), so...