GE Microwave vent fan replacement. My problem is that I need to replace the plastic squirrel cage

Question

My problem is that I need to replace the plastic squirrel cage blower fan on my microwave. I need to replace it because it melted when it sucked in flames due to a hot pan that caught on fire when it was left unattended. When I removed the fan from the motor and turned on the vent, the motor still worked. I found out that the fan assembly has a Samsung part number SMV-260UA and it is also used by Frigidaire. I also found out that the unit is very expensive, $150, from GE parts and only to replace the plastic blower fan. Thanks for your help.