Good job asking from the other perspective. Here it is (over simplified to state a point, you would need to do more research).

Let's say Tesla stocks are at 700. If someone offered 2k in addition to the opportunity to buy tesla at $620 / share, I'm sure many people will be lined up to buy it. Not only do you get $2000 immediately in the bank, you also get to buy tesla stock at a 10% discount. Not a bad deal.