There is some subtlety about talking about prices conceptually. Both sellers and buyers can make an offer or a bid at any price, but market prices are the result of sellers and buyers meeting - about making the actual exchange.
In this context, saying "sets prices" would mean that the buyer takes the price, not that the seller has made a listing at an arbitrary number. Offering 1$ for a car and not buying a car is not setting a price - neither is Asking 1000000$ and not getting an offer.
Rent prices are paid at all because there is a benefit to the land. If the Ask for the land is higher than the value, it will meet demand and validate the price.
> If this theory had been correct than raising taxes on businesses would not result in the increase of consumer prices.
Thats not true - economic incidence requires evaluation in a case by case basis. It depends on the relative market strength or demand/supply elasticity. For example, a tax on life saving medication is borne by the consumer, but a tax on skittles is born on the skittles manufacturer (as consumers replace skittles with other candy).
The point is that the economic incidence on unimproved land is very much against the landlord - he can't do anything with the unimproved land but rent it.
For longer, wider and more interesting historical analysis of LVT I recommend reading from source - Henry George and Provery and Progress, a book denouncing homelessness and land speculation in...San Francisco, 100 years ago.