Here's a somewhat simplified chart of Sandy/Ivy.
A Sandy board is a bit of a waste feature-wise, but there's also the possibility of getting a high-end Sandy for the same cash as a mid/low-end Ivy.
Keep in mind that the features listed on those charts aren't necessarily all-inclusive, most motherboard manufacturers will add additional chips at the sacrifice of a PCI-E lane, or USB port to add additional (generally backwards compatible) ports... PCI, Serial, LPT... or split a USB3 into more USB2...etc.