Purchasing additional points for Marriott Vacation Club

Hello everyone, new to Redweek here. I currently have a starter package of 1500 points per year with Marriott Vacation Club which we purchased at Ko Olina Beach Club in Hawaii.

If I wanted to purchase an additional 1000 points to add to our current package, how difficult and how long would it take to do so? I saw some ads that someone was selling them for as little as $850 to $1000 for 1000 points.

What do closing costs and transfer of title usually go for nowadays?

I think the closing costs can vary but typically range from $300 to $600.