LifeBloom

In the bottom left corner there is an option of privacy policy and Tos. They are the in game rules.

I don't think this is legal but trades like this happen often, but there are many scams. This one sounds like a scam. Do it at your own risk.

Very much illegal.
You're not allowed to pay or sell anything on Vortex for real money.
The only thing you can do with that is buy Mystery Boxes and a few other items in the official Vortex Store. Outside of that, there is no buying or selling with real money. Especially between players.

I figured that would be the case lol