Work: What did I charge?

I need to be more efficient about tracking what I estimated a job to cost. Whenever possible, I generate a “real” estimate with Quickbooks (QB), so it’s all in there, waiting for billing. And for smaller, “promo jobs”, I’ve taking to creating an empty folder inside the job folder, with the price I estimated in the name of the folder.
But the bigger jobs that don’t make it into QB also don’t get that little pricing folder. Ideally, I should just promise to always input big jobs into QB. But yeah… let’s be realistic about what I actually will do. And having to go back and search through emails 6 months old for a price just isn’t cutting it.
So price-labeled folder or…?