FYI, Delta (and I think American as well) has some insane deals right now on roundtrip tickets to Europe in August.
I have to go over to Finland for work, but my wife and I got tickets for Asheville-Prague, Helsinki-Asheville for $485. I was checking these routes earlier in the week and they were hovering around $1400. What's more insane is Asheville is usually expensive as hell to fly out of -- last year when we went to Finland we flew out of Charlotte to save $500 on my wife's ticket.
We're trying to do a weekend somewhere every time I have to go over for work, and the next cities on our list were Prague, Budapest, Berlin and all had this deal so we just picked Prague out of a hat (I've been to all but Budapest).
Deals still seem to be active when I checked Google Flights this morning.