I don't have any experience (thank god) with dog cataracts. But,our Westie has "dry eyes" and that ointment is expensive too, well if you consider $1 a day expensive. But, I don't use it twice a day... once a day and I may miss a day. I keep an "eye" on his eyes and if I see any clouding I go back to twice a day. By itself not a big expense for dry eye, just another of a list of special treatments the dog needs. I think he is typical Westie.
I just went through cataract surgery in November. It can be very worth it but there is a lot of aftercare and there can be complications. My dog did not have any issues other than the cataracts except for some inflammation. After surgery we had to deal with one minor ulceration and one fairly major ulceration. She is now healed and doing great. She is no longer fearful like she became when she couldn't see, and no longer slamming into walls either! We are still on anti-inflammatory drops once per day, steroid ointment 2x per day, and drops to lower pressure 2x per day. And this is 3 1/2 months later!
I would say if your dog's quality of life due to loss of sight has become poor, he is otherwise healthy, and he will let you put multiple drops in his eyes up to six times a day then go for it! Also don't spend your last dollars on the surgery as the drops are pretty expensive and you will need them for quite a while!