On ARMSLIST scammers try to pay with "Certified checks" that eventually bounce.
Cash or USPS MO only or a discreet PayPal (no mention of weapons, they are anti 2A)
Although I would take a check from @TheGman :)
It is right about just kinda up 7 from the left looks like a sideways paperclip there is a paperclip with an x on it just to the right. When you put your cursor on it the word Link appears.
Click it the paste the link in the URL box like this...