It's worth baring in mind that universities state their minimum entry requirements, not the average. In practice, the average achieved grade tends to be higher than the entry requirement.
I don't want to discourage you from 1/5 of the courses you apply to being an aspirational one as even if it ended up being a waste, you'd still have the other four as more realistic options. But I wouldn't have thought you had strong chances of getting an offer for a course that your predicted grades don't meet the minimum requirements for, especially for a subject like economics that's so competitive.
To me it comes down to this, are you willing to potentially waste 1/5 of your uni applications. If no, then don't apply. If yes, then I think you should go for it. If you successfully applied for an AAA course with AAB predicted, the offer they'd give would still likely be AAA though, so you would still probably need AAA eventually (though sometimes unis accept students with slightly lower on results day).