Where are you located: the US? Canada? Aus? NZ? That would help people make useful suggestions to you. $4.87 doesn't seem like all too much for 500 grams of cottage cheese...think of it in portions: that is five 100 gram servings, six 83 gram servings...either way it is under a dollar per serving. That isn't so bad, especially if you like it and it forms an important part of your diet.
I can also suggest that you shop around: there are no less than 4 supermarkets in walking distance from my house and one of them has cottage cheese that is significantly less than all the others. It is store brand, not name brand, but I actually like it quite a lot. I don't usually go to that store (I'm willing to pay more for the cottage cheese at my main store), but when I do I get a couple tubs. Basically what I am saying is that in my own experience, cottage cheese price fluctuates as much as $2 from store to store.
Finally, natural yogurt is an option and you can even make your own...however the milk will no doubt be expensive. That is actually the issue here, milk prices have gone way up so you are unlikely to find a milk product that is as inexpensive as you remember.