Need some help about my hammy?

i have a dwarf hamster named dumpling with an eye infection. ive already taken it to the vet and he told us what to do and everything. ive been giving her some eye meds that the doctor prescribed for her for a few days now and the vet told us that they might need to take the eye out. so i was pretty calm about that until my mom told me today that taking the eye out might cost us $500 to $1000 dolars and that we cant afford that so we would have to put her down. even though she said that there is a 90% chance we would have to do that, i got really depressed about the thought that MY first hamster might get put down. ive only had her like 2 or 3 months and if she was gone for good, my other hamster, sugar, would be sad and miss her. and my grandma (the only other relative alive) wont help pay for it if it happens. and i know i might get some answers saying stuff like "if you cant afford that, then why did you get a hamster in the first place?" its because we didnt think this would happen. i mean its not common that a hamster gets an eye infection, is it? so how can i forget about my hamster getting put down? my mom keeps telling me to forget about it and that theres a big chance it wont happen, but i still cant forget about it. any suggestions?