I try to study and see one source related to license fees and gambling taxes.
As said below.https://gaming.nv.gov/index.aspx?page=94SPECIAL NOTICE
In addition to State administered gaming license fees and taxes, various other license fees and taxes may be required by the Federal Government and local governmental units throughout Nevada. Applicants for gaming licenses and existing gaming licensees should contact these other governmental units for information regarding the license fees and tax rates administered by them. Inquiries concerning reporting requirements should be directed to the Tax & License Division of the Nevada Gaming Control Board.
In the quote above, I conclude that the licensing fee for each type of gambling and the structure of the gambling site, the fee depends on the rules of the particular country in implementing it, different countries have different gambling license fees, there are the cheapest and up to the highest as you said, but it all depends on how many years they take, for example: 1-20 years, just multiply the year.
As you said, probably among the casinos operating in Nebraska the most expensive licensing fees, I've also seen online casinos in the United States, not the middle part, the other part that caters to the casino, the license fee is around $30,000/5 year or $70,000/7 year, which is cheaply the license renewal fee is around $2800/year.
Conclusion: the license fee in Nebraska if it's $1 million, in 20 years, that means/year the casinos there have to pay a license fee of around $50,000/year, not much different from other casinos in other parts of America.