RepairPal offers a great feature at the top of the page, under the icon "ESTIMATE". Here you can plug in your vehicle info, and you can receive an estimate on what prices for many different repairs should cost for your car in your area.
Plugging in your info for your Sentra in Rochester, NY, it shows that replacing front brake pads and rotors should run between $340 - $449, depending on the establishment you choose to take it to.
I just did mine and paid $30 a piece for rotors and $28 for the pads all with a lifetime warranty. Purchased at our local O'Rielys Auto Parts or AutoZone. I'm in California so i don't know what your local 10 in every town corner parts store is. A socket set and a 3" C-clamp is all you need to change both. If you can't do it yourself the parts are under $100.00 and takes about an hour,(Labor at repair shop = $100hr)Total= $200.00 so anything above that in my opinion is taking you for a ride.