People can do well buying rolls of tickets but you have to remember something: These games are designed to make money... not to lose money. The state issuing the tickets intends to make money with them to help with senior citizens and the other things they do with the money. So typically a book is designed to pay out half (or so) of the cost to buy the tickets.
If they sell $10,000,000 in tickets then they want to pay out in the ball park of $5,000,000 so you can see that if all the tickets sell (or even most) that they WILL make a profit on the tickets.
I personally wouldn't buy a "roll" or "book" of tickets because it is too much money for me to play at once. That is the main thing you have to be careful of and think about. Do not play more then you can afford to play. Many people have gone to vegas with every dime to their name and hopes of hitting it big. Most come back empty handed.
It seems like you have played quite a large amount in the past few days. If you have that kind of money to play then more power to you but I would be careful not to over extend myself in hopes of winning.
I usually play scratchers when I can (right now I can not for sure!) and I play the jackpot games like mega millions and our local match 6 game. For the time being I have very little money and I am currently looking for a new job so my gambling funds are gone!
My advice: Don't buy entire rolls of tickets. If your going to play a lot of $20 tickets then I would buy so many of each from each of the stores around you. I spread my ticket playing around to the different stores in town vs playing all the time in the same machine. Techincally you have no better or worse odds buying entire books vs playing a few tix here and there but I've had better luck by far playing limited numbers of the same roll
