Haha no I don't imagine the price is exactly comparable to coffee grounds but I imagine they would work even better (though I've never tried either for this specific purpose). For what's it's worth though I was always willing to pay the price of it compared to clay cat litter which is dirt cheap...
Just to give an alternative. I used to really like walnut shell cat litter. I imagine it would give a similar result as the coffee grounds. They also sell walnut shell litter for pet birds but it's definitely cheaper to buy the big cat litter bags. The walnut shells are crushed to a similar...