The new 7x boards are definitely more expensive than their predecessors. Given that Ivy Bridge CPUs aren't really much of an improvement over SB, you'd be just fine getting a P67 board which can be had at slightly lower prices.
The 2500k is, unfortunately, the cheapest unlocked CPU from Intel. I really don't like what Intel did this round but whatever.
You might consider that route and get the aftermarket cooler later.