Did she not also request that Hazō also do that work?
Also, comparing the amount of time spent instead of the value of the goods exchanged is a disingenuous way to phrase it. As an extreme example, twelve hours of a surgeon's time is worth way more than than twelve hours of a cashier's time (since you could easily substitute the labor of the cashier with someone else). Trades are always based on the valuation of the goods or services being exchanged, not solely on the time the services entails. A Clan Head like Ino would absolutely operate like this.
We are going to be paying her for that mission, so what we're really purchasing is her forfeit of the scroll and a guarantee that she'll make herself available for it. Both valuable things, to be sure, but not nearly at the level of over two and a half thousand Goo Bomb seals which each can allow even one of her weakest genin to hit well above their weight class.