If you are fine with my winning of the English speech contest, I don't think it's such a big deal.

如果你对我赢得英语演讲比赛没有意见的话，我认为这没什么大不了的。

youdao

Actually, I say actually it's not a big deal.

其实，我是说其实这没什么大不了的！

youdao

If I lose a dozen photos of thousands I've taken, it's not a big deal.

如果我把几千张我拍的照片弄丢了，这不是什么大事。

youdao

Thats a really big deal. Without it, anything like the modern stock market, I'd say,is impossible."

VOA: special.2010.03.05

FAO Schwarz is a big deal toy store here and I'm not sure if it's on Fifth Avenue, maybe...

AO Schwarz 玩具店是这边一个很大的玩具零售店，我不确定它是不是在第五大道，也许是吧……

小心超额消费 - SpeakingMax英语口语达人

While this distinction is a weapon in the war of words between the carriers, I doubt it's a big deal for most average users.

WSJ: New Verizon Service Bests AT&T in Call Reliability for iPhones

"I think the big deal is that it's not a big deal, and I think that's cool, " Washington said.

CNN: Kerry Washington talks Olivia Pope, slavery and politics

"I don't think it's that big of a deal, " he said.

WSJ: NCAA Tournament 2013: The Great Four-Letter Phobia