I got this Raspberry Pi Model B rev 2 (512 MB RAM) from Farnell (UK) in May 2013 at a price of 33.07 British Pound Sterling (about 39 Euro).
This is my 2nd Raspberry Pi and is the first 512 MB version of the Raspberry Pi Model B, released in October 2012.
The Raspberry Pi is a credit card sized single-board computer developed in the United Kingdom by the Raspberry Pi Foundation with the intention of stimulating the teaching of basic computer science in schools. The Raspberry Pi Model B (RPi 1 Model B) has a Broadcom BCM2835 system on a chip (SoC), which includes an ARM1176JZF-S 700 MHz processor, VideoCore IV GPU and 512 megabytes of RAM. It does not include a built-in hard disk or solid-state drive, but uses an SD card for booting and long-term storage. The first generation had only a 26 pin GPIO header, which was replaced by the standard 40 pin GPIO header in the next generation Raspberry Pi.
Some addition info via the 'cat /proc/cpuinfo' command:
Hardware: BCM2835, Revision: 000e (Manufacturer = Sony UK), Model: Raspberry Pi Model B Rev 2