It really depends on your goal and purpose. So you should ask yourself if buying this miner answers the question of need and want.
If you are aiming for profit and money, then don't buy one. You can't find anywhere in the world that is a profitable USB miners. But it doesn't mean that for those right person it doesn't make excellent gifts also.
Are you looking for a stick miner, which is similar to a flash drive, or maybe a larger one that will just connect to a USB and have its own power supply?
By looking at the stores online, you can see different options that also varies with a variety of price and versatility. If you want to gift someone that ages like a teenager and interested with the technology, then what you are looking for is ASICMiner Block Erupter.
21 Inc. Bitcoin Computer have price costs as much as a low-end tablet computer. Their differences isn't just in their relative mining power but also in what they can do.
The ASICMiner will just be utilizing your computer software running in order to mine bitcoin, on the other hand, 21 Inc. Bitcoin Computer is standalone and it can mine of its own and does a number of other things.
Market these days have couple of nice and well-priced USB stick miners. GekkoScience Compac is one of the option which produced independently and unfortunately in a very small print run.
The original price range might be differ up to $25 per unit by the time you read this. It means that options in the market are really great. They’re able to produce at least 8 GH/s (gigahashes per second), and up to 11 GH/s, which is incredible for a USB stick.
You can calculate what that will produce in terms of Bitcoin using this Bitcoin Mining Calculator. At current, it produces about $0.50 per month. Not exactly a lot–but as I said at the beginning, these are for hobby purposes, not profit.
Another good option is Avalon 3 Nano, if the above options aren't available. You can just have it for like over $25 and it was released in early 2015.
It will generate a consistent 3 GH/s, and is at a better price range for most purposes. However, the Avalon 3 Nano is a little harder to set-up, configure, and use.
If you just want to buy a device just to educate someone that has interest about Bitcoin, then you may decide you don't care about the hashing power of the device. For that option, you can have the ASICMiner Block Erupter. The price of these devices are available in less than $20 straight from Amazon as well as many online distributors that come with perfect, simple instructions and have lots of tech support available.
There are options also like Antminer R1 that will mine Bitcoin for you in the AntPool Solo Pool, which means it is attempting to win the proverbial Bitcoin lottery. You don't have this much luck to succeed, but it’s also just a fairly normal wireless router, and it’s priced competitively in that field.
Moreover, it’s just a kind of neat idea: a router that mines Bitcoin is just one possible device that can do that. What’s next, microwaves? Who knows.
There are a lot of choices and options you can find in buying USB Bitcoin Miner out there. But at the end of the day, it is you to decide what you need and what you want in order to succeed on your goals.