Cisco Layer 2 Switches (NBAR) and Lync QOS

I have read through several other posts about QOS/Cisco etc but my issues seem to be rare.

1. Our enterprise has layer 2 switches (the cost to upgrade the switches is huge)
2. Trusting PC's to DSCP mark is not an option (network peeps concerns)
3. The port range settings for Lync traffic does not work (refer back to #1)

I keep reading about NBAR and that is is used to detect VOIP traffic at the packet layer.  My understanding is that NBAR runs at the layer 2 level.   

My question is this - can I do something such as 'setting Lync to use G.711 and use NBAR to QOS the traffic'?  Is that possible?  I read that there are even Lync definitions in the NBAR database.

if my post is helpful - please click on the green arrow. (please excuse, in advance, any perceived sarcasm/humor - as I often forget it does not translate through text) :)