Help Athena The Rat

I recently found a mammary tumor on my heart rat, Athena. I took her to the vet and confirmed that it is indeed a mammary tumor. It's slow growing, but will need to be removed so it does not impact her quality of life as it grows. As it's still small, the cost for the removal ONLY will be about $342. The vet reccomened a spay to hopefully prevent the tumor from returning. With the spay, the total cost runs to $539. Any and all help is appreciated. Thank you so much for your support. Athena and I both appreciate it.