I didn't really get your question, ha. No, the level 40 gift boxes are a sprint for 3 days, which people who don't want to spend Cash Shop recharging buy in-game off other players.
If you need the money, take the money. Once you start using a sprint, you feel really slow after and want to buy more ~ I can't play without a sprint anymore, it's terrible ha.
But if you need the funding, sell it. It's worth about 10m, I saw them vending for 12-16m a few days ago but weren't selling, which is why I said 10m would probably have better luck.
But yeah, I couldn't tell if this is your first mmo and you were confused about how it works or what, ha.
All the level up box rewards, also free free to use the TO Price Check
forum if you're curious about pricing.