Hunting in one of the one PP units sometimes gets you a good view of guys wearing orange hats seemingly driving on every two track. One group of fellows gave me the unsolicited advice "bring lots of gas and lots of ammo". I had watched that group and a few others all morning driving around, plinking at long range, and generally messing up the area. The animals were spooked badly and many of them left the BLM land and headed to the private ranchland.
Sometimes you will luck out and not see much pressure on the BLM land. For a first time group I would think that paying for access to less pressured hunting ground would be worth it, others will surely disagree.