Vodka's taste notes are so subtle that most people cannot differentiate between different brands by taste. Vodka is a neutral spirit. There's no aging involved. No oak barrels to add flavour. Vodka is distilled to create a spirit that is as pure and clear as possible.
The slight differences in the taste of vodka depend on the grain used, and the number of times the spirit was distilled. It can only be noticed when drunk, straight, frozen straight, or with distilled ice.
Vodka used in mixed drinks will be over powered by the taste of the other additives in the drink. The wide variety in the price of vodka is based on product marketing. What is essentially the same product is marketed at prices from $8.00 to $60.00.
You should not make your choice based on bottle, label design, country of origin or brand.
Cheaper vodka when used in mix drinks will taste the same as the more expensive vodka.