Well - where would you wear it - and do you already have clothes that more than covers you for that? If not, then work out how often would you wear it a year, and for how many years? Divide the price per wear and that might be your justification right there.
On the downsides, I do think it's overpriced for the material, will likely look cheaper than it is in real life, and will be a bit sweaty if it isn't a cool day..