still another text message stating "You have been selected for a FREE $1000 Best Buy gift card!" that originated from this number. it also happens to be my area code...how do they do that? What is their purpose? Just malicious?

This is a scam, stay away from it. CallerID numbers can be spoofed https://en.wikipedia.org/wiki/Caller_ID_spoofing so CallerID cannot be trusted. The $1000 gift card is a lure to make you jump through various hoops (take a survey, sign up for a book club, etc.) but you will end up paying a lot of money for the crap they make you sign up for to get the card which doesn't really exist, it's just a ruse to get you to sign up for crap. They're not giving away money, they want YOUR money.