Hmm. In Cold Days, Harry goes off on a tangent about how bad guys tend to keep using the same locations, like the Full Moon Garage in Fool Moon and Proven Guilty. He's specifically talking about the warehouse Mac and Pals are held hostage by the Redcap, but it makes me think that the reverse might be true; the Good Guys might want to use the same locations as well. It could very well be a product of magic in some regard, though I think Marcone was primarily motivated by self-interest. They needed a symbol of unity and resistance to the Fomor/Other Bad Things incursions, and setting up shop on Harry's old plot makes sense.
It's also a residential area, which is a mild deterrent. Plus it's right by Mac's, so there's already a hub of magical community activity near at hand.
All that aside, I imagine that Marcone felt particularly smug about handing Mrs. Spunklekrief a check for several times the value of the land (unconfirmed, I just have a feeling that he did something like that).