Vanek, Moulson, Hemsky, Stempniak, Ott, Callahan, Stewart, Goc, Legwand, etc, all moved to strengthen playoff teams. As you said, for the most part, prices were cheap (outside of Callahan)
I think Jarmo made a huge error by subtracting Gabby (while keeping the payroll) and then not adding anything. I've seen plenty of contenders stand pat, or add, but to subtract without adding was IMO a really bad move. No, I don't think he could have traded for Kopitar or something crazy but yes, I think considering our stud young guys, plethora of picks last year and good prospect base, we could have parted with some draft picks to add a guy like Moulson if we were going to part with Gabby.
I'd have been fine with standing pat with a healthy Gabby or if they really wanted to be rid of him, at least do something to bring a piece in that can play/help the playoff run.