Specifically, $27ish dollars shipped, and basically the cheapest still reasonable way to get into SDRs. Receive only though, so while you can explore the spectrum below about 1.9ish GHz, you can't play with it
For a more capable model, I would recommend the ADALM PLUTO from analog devices.
It's ~$150 USD (if I remember correctly)and has a range of 385 to 3800 MHz @ 20MHz bandwidth, but a very simple hack increases it to 70 to 6000 MHz range @ 56MHz bandwith. Check here for more info on the hack: https://www.rtl-sdr.com/adalm-pluto-sdr-hack-tune-70-mhz-to-...
Having just switched to an RTL-SDR.com from a myriad of cheap ones, I'll say that yours will get you started but picks up a stack more noise. You'll also want a better antenna.
Specifically, $27ish dollars shipped, and basically the cheapest still reasonable way to get into SDRs. Receive only though, so while you can explore the spectrum below about 1.9ish GHz, you can't play with it