Just thought l would put my two cents in and post my solo strategy.
First round, l just stab them, second round l shoot them and then stab. By the end of round 2 l should be close to three grand or more, especially if l get a nuke and then take the elevator down.
Round three has started, l jump across and open the power room and grab one of the parts to the
sliq-gun, turn the power on and run out of the room, drop down a level and grab the AK to build points. I start assembling the sliq-gun and use the elevator to get the other parts, and l do not open up another door at this point. Once the sliq-gun is assembled l take a ride to the roof.
It really is random at this point depending on where jug is located. If fortune smiles upon me and jug is on the elevator l take up, then it is easy. I hold up on the roof and build my points, l could shoot a small burst into the body and then knife, but l'm usually a headshot whore and I love to see those heads pop!
The jumpers usually come by round six, by this stage l want to have bought the bowie knife and start slashing those jumping jacks. If I've had a good run with double points and have 2 grand and double tap is available l won't kill the last jumper till the elevator comes up. Like l said this is random depending on which elevator the perk is on and how many points l have made. I kill the last jumper, and l will get 2 extra grand. I don't grab the perk bottle yet, l will get double tap or mule kick and then get the random perk. I will then have three perks at this stage.
Then the rest is easy, l head over to the food bar area and run trains there and make a heap of points, hit the box, pack a punch and l'm set. Then its a matter of hitting the gravy train and mowing through the rounds. It's worked well for me as l've been to 50+ a few times till l either get bored or l fluff it and die! Hope it helps!!