Forget that stuff about the standard lottery having billions of combinations - it’s not correct.
If a lottery doesn’t allow the same number to be used twice, the number of combinations available in a 6/51 lottery is 18 million. For a 6/54, it’s 26 million.
Theoretically, if the dollar value of the jackpot is higher than the odds of hitting it, you have a positive expectation, meaning you make money with every ticket you buy. There is an Australian syndicate that has thousands of members and acts almost like an investment fund - they collect funds to buy lottery tickets when a lottery jackpot hits a certain amount.
There are complications: First, someone may tie you, or possibly even two or three people. Second, there may be secondary jackpots that come out of the prize fund. For that reason, the lottery syndicates won’t be interested unless the jackpot is much, much higher than it has to be. Perhaps two or three times as much.
Finally, it’s really hard to buy that many tickets. When the Australians beat a lottery in the U.S. a few years ago, they had a complicated infrastructure of money men, runners to hit all the lottery machines they could find, etc. Even so, they ran into a bunch of problems and wound up only buying about 75% of the tickets. They still hit the winning jackpot and won the whole thing.
Incidentally, as an individual buying lottery tickets, it’s pretty much irrelevant how big the jackpot is, due to something called utility theory. Basically, the utility value of the lottery doesn’t really change if the jackpot doubles, because the time and money it takes you to play vastly overshadows the value of the money multiplied by the chance of winning.
Utility theory is very interesting when applied to gambling. Most of the work on utility theory has been done in the insurance industry (insurance is a ‘bad bet’ in that insurance payments have a negative expectation - you expect to lose that money, yet people almost universally believe it’s smart to buy insurance. Utility theory explains why). In gambling, utility theory tells us things like why poor people buy more lottery tickets than rich people, why people buy them at all, etc.