yeah, the OTD can be painful. I ended up at just under $7K OTD for my Speed Four.
The 4v Ducs are beautiful. A couple of issues...first is riding position. Much more "torture rack" compared to a Monster or Triple (even compared to my Speed Four with clipons). Second, maintenance costs are significantly higher (more valves to adjust). Third...you'll lose your license
Richard (motion) has a 999 I believe, and likely has ridden other bikes. I've never ridden a 4v Duc, but aspire to.