John can not buy the 2k monitor.
If a person doesn't have enough money to buy a product, then that person can't buy it. Monitors are products. 4k monitors are more expensive than 1080 monitors and 2k monitors. John is a person. John doesn't have enough money to buy a 2k monitor.
∀x ∀y (Person(x) ∧ Product(y) ∧ ¬HaveEnoughMoneyFor(x, y) → ¬Buy(x, y)) ∀x (Monitor(x) → Product(x)) ∀x ∀y ∀z (Monitor(x) ∧ Monitor(y) ∧ Monitor(z) ∧ FourK(x) ∧ OneOEightO(y) ∧ TwoK(z) → MoreExpensive(x, y) ∧ MoreExpensive(x, z)) Person(john) ∀x (Monitor(x) ∧ TwoK(x) → ¬HaveEnoughMoneyFor(john, x))