Those were Ferguson's BRM guidelines when he wanted not to go broke during his challenge. Personally, I try to play under those guidelines, because I am not nearly as good a player as he is. So far, I have not gone broke. At least, not since I have become a lot more serious and careful a player. I busted plenty, redeposited plenty, the first couple of years -- but it was fun money, entertainment. I have not redeposited in over a year. I still have fun, but it's a less wild sort of fun, more grownup. Sometimes it gets boring waiting for a hand and I am tempted to play like I used to when I thought that TV poker was accurately depicted -- but now I find it more enjoyable when I do not toss my money away. Go figure. It took a major attitude adjustment to play properly. Or even as close to properly as I have managed. Some days are better than others.
For me, $50 would be too little to start with, as I have a hard time caring about 1 cent raises at cash games or $1 SNGs-- but if you look at Mr Freerolls's second stats, you can see how, with conscientious grinding, it can be built into a bigger roll. Basically, you have to divorce yourself from real-life payscales, unless you are willing to deposit a substantial amount to play at a level that may matter to you. But it's really risky -- because it would matter to you, I suspect, if you lost a couple grand. Still, redeposit $50 twenty times and, hey, it's a grand. Might you actually prefer building the money you deposit by carefully reducing the risk that you will need to redeposit? Your call.
The better plan would be to develop your ability to be patient. About what cards, what level, everything. Patience is the key.
Books do not fully prepare you to play. I can sum up all books in one sentence: Play good hands, dump the garbage. You have to play a lot for much of the other book knowledge to mean anything. And you still might not be good enough to play with the big boys. Some people can beat the micros and low buy-ins consistently, but run into severe problems when they try to move up. The way around that is to find the highest level you can beat (moving up only in accordance with BRM), and then learn to multitable, moving up in number of tables until you hit a point that you lose consistent results. Then, periodically, after you rebuild your roll from your last fiasco at a higher level, try the higher level again. Some special people can keep moving up and up profitably, most cannot.