Maybeeeee buy a Microsoft press book with some labs, etc etc... Realistically though, you are best funnelling your money into a used HP G5 or any other server of similar vintage, installing Server 2008 R2 and HyperV. HyperV is a Virtualisation platform which will enable you to host lots of servers within the one server. This will give you experience standing up servers, as well as the basics of virtualisation (which most companies are going ape-shit over at the moment).

On each of those servers, download and use trial versions of products, as well as set up the fundamentals. Set up a mock business environment, a domain controller, an exchange server, MDT or SCCM for imaging devices. The list goes on.

Microsoft offers Server 2008 R2 for free if you are a student, or you can download an eval edition which lasts a couple of months only.

Technet, Microsoft's online resources are fantastic, go through the guides on how to set up a Domain Controller, how to deploy devices, applications etc etc.

I think this is a better spend of money and time, you are gaining real world experience, which is what I look for over 'book smarts' when employing someone.

Good luck mate.