Many coders such as myself started out with Access and VBA, and ASP with VBScript is a natural extension of that. Also in terms of developer support it seems like there are a lot more ASP help sites than there are in PHP but of course a big part of that is probably because the
www.php.net site is so awesome.
And why use ASP when there is ASP.NET?
Well there's that little thing about shelling out $500 or whatever for Visual Studio. And the learning curve for ASP.NET is steeper because it is more complex. And if one is used to using Visual Basic in Microsoft Office products such as in code behind the form of an Access database, then the transition to classic ASP is a natural one as the syntax of ASP using VBScript is similar to that of Visual Basic while the syntax of ASP.NET is generally more like Visual C++ and JAvaScript with the semicolon after each line of code, etc.
But if you're used to PHP, I'd really think about switching Web hosts.
For a low-priced Web host you may want to look into
www.best-machine.com where currently for $4.50/mo total you can set up 5 domains (i.e. separate Web sites).
I've used them for some low-priced situations although if you need SSL they may not be what you're looking for.
And you could buy your domains from a domain registrar such as
www.godaddy.com.