The description in the book describes touching the right hand in front of the left foot while the right leg goes up, then says to repeat it with the left hand going down, and that you've completed one rep when you've done that. Then, it says to switch legs. So, when doing ladders (1 rep, then 2 reps, then 3 reps, etc), is one to do the right leg twice as one rep, then do left twice, right twice as the second two reps, and so on? Or is "one rep" supposed to be twice on the right and twice on the left?

I would consult his website, but [the forum](https://www.marklauren.com/forum/) seems to perpetually be down.
['https://fitness.stackexchange.com/questions/28699', 'https://fitness.stackexchange.com', 'https://fitness.stackexchange.com/users/8039/']
If you consider yourself handy then you could consider building some weightlifting equipment yourself. It is cheap and surprisingly simple.

Although I do recommend that you do buy the barbell since making one out of wood or other common materials would be considerably weaker or larger if you try to maintain the same strength. 

[Buff Dudes](https://www.youtube.com/channel/UCKf0UqBiCQI4Ol0To9V0pKQ) have a Youtube channel where sometimes *Buff Dad* has tutorials on how to make Gym Equipment. [This](https://www.youtube.com/watch?v=6dy5eyMDt3c) is an example for a power rack. I've found that the procedure is quite simple and doesn't require any advanced tools. The material is mostly wood so it is very cheap.

As for weight plates, there are again many tutorials on Youtube ([this one](https://www.youtube.com/watch?v=EpwewKou_R0) for example) where people show you how to make weight plates from concrete. It's about $5 for a 25kg bag of concrete, so you could make ~30kg (some water is retained from curing, I'm not sure how much) of weight plates for only the cost of a bag and a mould which would be less than $5.

Although it would take a considerable amount of time you could build yourself a home gym for a couple of hundred dollars.
Get a pullup/chinup bar. You can get one for about $20.

Buy a couple of parallel bars where you can do dips. If you have a couple of sturdy chairs, they will do.

Pullups, chinups, dips, pushups, planks, bodyweight squats are all great exercises that could make up for a very decent routine.