Cost of a Raspberry Pi
Although Raspberry Pis might seem cheap to buy, the costs can add up by the time you add on various accessories. At the very least, you need a power supply, an SD card (hard drive) and an hdm1 cable. This brings the tally up to $70 or so; depending where you buy the supplies. After you have these basic supplies, you can can turn on your tv, start your pi and install an operating system on your SD Card. If you are lucky, you have a mouse and keyboard that is compatible with the Raspberry Pi. Otherwise, you will need a compatible keyboard and mouse which can run $20 and up. At least now, you are up and running anywhere from $70-$100.
The Raspberry Pi comes without Internet, so add on another $5-30 for an Ethernet cable. A cheap dollar store model is usually sufficient. A wireless usb dongle is another $15.
By the time your Raspberry Pi is up and running, you can expect to pay somewhere around $100. As an owner of 3 Raspberry Pis, I still find them very useful for my intended purposes. They use very little power, take up very little space, make excellent storage devices and can run local php / mySQL scripts.
Would I buy 3 again? Yes.