Eye Removal for Cat with Glaucoma

My cat Albus is a 10 year old Siamese mix and one of the sweetest cats you'd ever meet. He recently developed glaucoma in one of his eyes and the vets and specialists aren't sure if it's caused simply by inflammation or a cancerous tumor, so it needs to be removed. The surgery is around $1200 which is the goal I've set for this - every penny would be appreciated! It's scheduled for the end of July.