Hi Anchor - welcome to the forum
I am not an ASP developer, but have done quite a bit of PHP. Hopefully there will be some ASP experts who can also comment on this too...
Personally I would say they are quite comparable and they achieve the same thing. There are certainly quite a lot of people that say ASP, although a more complex language, is more powerful than PHP. However, because of the added complexity many people do not use it to its full potential and create messy code. It also strikes me that the ASP programming is quite VBish, whereas PHP is more C (or C++) ish, which ever you prefer I suppose.
Cost wise, ASP is not free - you need Internet Information Server (IIS) installed on the Windows server and also connectivity to databases is really quite limited to MS-SQL (another product you need to by from MS.) Whereas with PHP, its free and easy to connect to MySQL etc... Another advantage of PHP is the huge number of things built in, from ftp to email to encryption. I don't *think* that as many of these come with ASP as a default, and often you need to purchase the extensions.
I have also heard that PHP is slightly faster than ASP but don't know. Some people say there is more demand for ASP developers than PHP developers too - again not sure
