If you're into handbags etc...but don't like the Milan prices, take an hour or so out to go into the fashion boutiques where they sell the real deals and then take 30-50 Euros out in 5-10 Euro notes and head out onto the streets. Look for (the generally African) sellers on the side of the street that sell the leather goods (mainly knockoffs of the 'name brand' handbags/wallets/purses (LV/Prada/D&G etc...) most of them will ask for silly money, but generally about 25-30% of their opening gambit is their cost price, so offer them 15% and work up to no more than 30% from there. If you're lucky, you'll get a production discard (lining sewn in upside down/minor stitching defect), worst case you'll get a reasonable knock-off. Make sure you test the bag a bit (yank it about an make sure the stitching is good), and if it breaks, walk away (they're not supposed to be selling fakes anyway, so they'll shout, but won't follow/hassle you)
If you're more into buildings, then the Duomo is worth a look, as is the Galleria Vittorio (and who knows, if you win the lottery you may even be able to afford something in there

)
Also I found the Castello Sforzesco quite entertaining.
You're a bit too far noth to be in serious wine country, so that's probably out (unless you fancy an internal flight down south). It's also very worthwhile asking the hotel concierge what he/she recommends, as chances are they will get commission from some of the travel guides in the area and will be able to recommend a few decent days out sightseeing.
Finally, make sure you eat out as much as possible. The Italians are mad about their food (and for very good reason as it transpires they're really quite good at making it) and decent meals can be had for great value.