United Airlines voucher - Asking 350$ for 400$ worth voucher

Valid till 11th July. Selling it because I don't think I'll be travelling till then.
Save 50$ on your flight tickets by using the 400$ voucher which I'm selling for 350$.

FAQ:

1. Not an e-voucher.
2. Yes, I'm willing to accompany you to buy the tickets with the voucher. If the vouchers don't work, you don't need to buy them.
3. Validity date refers to the date before which you should use your vouchers - the flight ticket could be for a later date.