Well, yes, another vote for the need to get things straight with your wife. I perhaps don't see the money as the biggest issue, though I would agree that large amounts like that [10-20 thousand might not seem like a ridulous amount to you, but would your wife agree with that?] should be talked over.
What I see as the bigger problem is the dynamics of these extra-marital relationships. You both were in the swinger scene, your present relationships started out there (is this true with all your wife's lovers?), but - and here I'm reading between the lines - whereas your wife seems more interested in the sexual thrill of another lover, and quite happy to move from one to another, You've "fallen in love". For her, having other lovers (and not sharing them with you) is what's important. To you, the other PERSON is what's important. Is that the way you see it, or have I got the completely wrong end of the stick? Another question: would your wife see it like this?
Again reading between the lines (and this time perhaps cross-eyed), it seems to me that your wife is somewhat bored with you sexually. You started out swinging together, and then she said she wanted to carry a certain relationship further... alone. Since then she has started other [purely sexual?] relationships alone.
I don't know much about swinging. Is it a couple activity? If she goes out alone, is that swinging or an open relationship? What you certainly have is an open relationship, but you are tending more towards polyamory (emotions involved) and she towards having "a bit on the side" as the Brits say. That - at least - is my take on it, without knowing all the facts. And that's what I think you really need to work out with your wife. [I've just been informed that this cyber café is closing in 4 minutes, so I've got to leave it there.]