 WDBO. Sell your home stress-free this summer with a guaranteed offer from Mark Spain Real Estate. Hi, this is Mark Spain, and our offers are the strongest in the industry. When you get a guaranteed offer from Mark Spain Real Estate, you can sell your home stress-free and avoid the hassle of costly repairs. There are no showings, no open houses, and no stress. One of our clients, Caitlin, said, Working with Mark Spain Real Estate was so easy, and they exceeded my expectations. Find out what your guaranteed offer will be and close in as little as 21 days. There's no obligation.