Where to get a copy of Visual Basic 6.0?

I wrote an application (DLL and EXE) for a buddy many years ago using Visual Basic 6.0. I kept the source code, but not the VB6 application. He wants me to make a few updates and I need a copy of VB6 to do this. The updates need to take place in my Active X DLL project. Where can I get a copy of VB6? I noticed they were on Ebay, but going for $300 per copy. Is there anywhere to get a less expensive copy? I just need to update this one application and do not plan on building additional applications in VB6.

I tried installing Visual Basic 2008 Express Edition and converting the project, but it threw all kinds of errors on me.