It will be worthless much faster. Expect a massive pricedrop after a few months. A year later they are even worthless on Ebay, so they will have no resale value. This means Bitcoin have to jump massively in price to earn some money here, which wont really happen that fast.

Buying Asics is a high risk and gambling. Also they are noisy as hell, hold that in mind!

If you want to invest, buy BTC, LTC, ETH instead and enjoy your profit soon.