Bladder stone removal surgery for my Dog Polo

My dog Polo has been struggling with bladder stones.He was misdiagnosed twice before finding it for a UTI. The stones unfortunately cause him discomfort and blood in his urine! The 4 previous vet bills have unfortunately exhausted us financially. The vet determined that the only way to treat him is surgery to remove the bladder stones. The surgery is $3,000. We deeply thank you for any help as does Polo!