I’ve got a battery power combo amp too, and have used it like you for Halloween things and other light duties. But it cost under $200. Well under.

I think that’s the appropriate amount to spend on something you actually NEED so seldom. And need high volume and great sound even less.

But the EV’s might make excellent fill in speakers at a huge venue where good sound and the Bluetooth connectivity and no cables are a strong positive, and where your main speakers don’t project well

The thing I think makes the decision is, just how often will these be the ONLY solution that works for you? I might actually REALLY need these once every couple of years.