Theoretically, you don't need to spend anything, although it would take a fair amount of time to learn.
Microsoft has a server-side language called ASP (Active Server Pages) that will work with Access and work well, once you learn it. It's what VP-ASP (I believe) is based off of.
www.asp101.com
www.haneng.com
www.4guysfromrolla.com
These three links should get you started.