Mileage Run Discussion - Need 8k miles for PM on DL

Live in NYC. Would prefer to earn it on a weekend in June to get the most out of a 75% RDM promo expiring June 30. Would prefer to be in NYC on June 9 for the Belmont but not an absolute. I was looking hard at the lowish fares to DUS/BER as its the right mileage but waited too long and the remaining flight combos are not so good for me (would have been a great way to get a Park Inn for the club Carlson promo too). I still might book that (though probably not in June as the extra 6k RDM are not super important to me) but would like to hear about any alternatives. I'd appreciate any advice, thanks.

Have you looked at transcons? May be cheaper than MRs to Europe.

What's your price range?

I'd like to keep it under 5cpm domestic but would pay more for a good European destination. Transcons have been expensive in June though I think they dropped down to around $325-$350 for certain routes. But I'd rather fly to Europe for less miles and double the price.

Edit: By kess i mesn less than double the transcontinental miles.