Multiple citations with pages using BibLaTeX

You can use the multicite version of \cite:

\cites{ref1}[2]{ref2}[3]{ref3}[4]{ref4}

This will roughly give the following output:

<label1>; <label2>, p. 2; <label3>, p. 3; <label4>, p. 4

In general \cites takes arguments of the form

\cites(<multipre>)(<multipost>)[<pre>][<post>]{key}[<pre>][<post>]{key}...

where the first two arguments (<multipre>)(<multipost>) serve as an "overall" pre- and post-notes and the remaining arguments can be repeated as necessary. Citations are printed in the order given with compressed citation labels depending on the style.

For further details refer to material on "qualified citation lists" in the biblatex manual.