The phrase "amount of variety" is correct and usable in written English.
You can use it to refer to a wide range of different things. For example, "With such a large amount of variety available, it’s impossible not to find something that I like."
Hamlet would seem to offer an unusual amount of variety.
Seeing them in a group, however, emphasizes a careful system that accommodates a startling amount of variety.
While the controls are difficult to master at first, the amount of variety on offer, particularly when bowling, is hugely impressive.
He's right, and at the moment, there is a remarkable amount of variety in the upper echelons of the country chart.
There's an admirable amount of variety – you must pilot tanks, boats, armed jeeps and quad-bikes, and man fixed guns in helicopters.
Besides, he said, given how few instruments are used "in 'Night Music,' the amount of variety in the orchestration is amazing".
That is to say, at each moment t, the amount of varieties that can be used in the production of output is given by the amount (and number) of innovative goods of previous periods, as well as those that are introduced at moment t.
There are an infinite amount of varieties out there, meaning there's a beer out there that matches your ideal taste.
The answer, in part, is 7-Eleven's time-based distribution system that handles enormous amounts of variety with seeming ease.
According to the company's David Perrin: "Our newer open-plan areas have huge amounts of variety, with kit such as dumbbells, kettlebells, steel bells and brightly coloured plyo boxes.
As Ashby predicts, "Any regulator able to confine the fluctuations in the system to be regulated must not only have adequate amounts of variety available to control that system but also be or have a homomorphic representation of that system" [26].
