Theory : Tanya's money is cursed

And that's why it brings death wherever it goes.

Season 1 : Tanya's around and that's why there's a murder (she s even one of the thing that drove the guy crazy, when they spent the day on the boat.

Season 2 : Tanya's money is directly involved in the rampage

Season 3 : Greg settled near the hotel with Tanya's money, and we already know there will be death again (probably involving Greg somehow).

So maybe we'll discover it was dirty money from the beginning, but Belinda could finally get it and open her spa and break the curse