As for me, I am not the ultimate supporter of MS tools, and I really hope that MonoDevelop catches up (I mean it catches up in many ways, it is really fast in operation, and it seems it gets better and more compatible) but tools that are invested with big money (as MS tools or Office is), is as better as MS wants to put them into Linux. It increases the value of the platform. Imagine AutoCAD or SolidWorks: if they don't work with Linux, the engineers will not use it. We can argue for lifetime that FreeCAD is better, but engineers will not care.
Am I going to pay for a MS tool in Linux? Yes, why not? For most of the software, I don't buy it, my company buys it for me, so why should I care? I would care to have an optimum development experience, and if this would mean that I need VS, I would pay for it.