On the contrary, I think buried is easier than other zombie maps. You can just keep moving in all areas and they all spawn behind you for easy line up kill. Especially that you can easily get the LSAT before round 3, you can easily pile up points.
What I did that worked is pile up points until round 12 by doing a circle run from the spawn box area or leroy's cell, going to the saloon, then left into the power building, climb the left stairs to second floor, then jump to the side roof of the next building where you can find buildable parts and continue to the side roof of the bank (this is where it is easy to line them up because they follow a straight line on the side roof, this is where I also put the head chopper) and then jump down to where you started (in front of leroy's cell).
Then by round 14, you will have money and should have better weapons so you will need to pack a punch so you have no choice but to go on a date with the ghost ladies in that spooky house. Ray gun works best and killing a number of ms floaty gives you free perks.
Then you build all buildables and do the zombie train.