Lots, Every year I drive 24 hours from Wisconsin to Utah to spend a week hiking, camping, and exploring canyons on BLM land. It's incredibly enjoyable and a very relaxing getaway, due in no small part to the fact that it is not one of the beautiful parks that are filled with people. If I so desire I can spend a week out there and not see another person, and I'll be devastated when that gets taken away. For those of us who are ok with some risk in our activities like canyoneering, BLM lands are crucial. Most parks are afraid of being sued when someone gets themselves in trouble and don't allow fun stuff like that.
Ask yourself this: what benefit do you personally get from my having access? Let me answer that question for you: when you're hoping to snag a camp spot in Mount Rainier National Park, you can because I'm camping on BLM land. You want to go see Mount Rainier, I just want a place in the middle of nowhere to drop the VW camper for a weekend. But the BLM land went away, so even though I don't give a shit about viewing a big volcano, I'm taking your camp spot because there's nowhere else left.
...and we could make some money selling it.
"A representative for the interior department, Mike Pool, who weighed in on a version of the bill in 2011, said selling those 3.3m acres 'would be unlikely to generate revenue'."
IOW, we can sell it to our campaign contributors for pennies on the dollar, and it's all perfectly legal (thanks to a recent change to House rules by Republicans).
I'd rather camp here: http://www.andyintherockies.com/photos/bartlett_3937.JPG
It's a different experience from the parks.