I'm certainly no expert but my reaction is that the specs of the one in the deal are rather poor. The RAM isn't very much and the 4GB memory is a pittance. There is no mention of an SD card slot. Neither is there any mention of USB, HDMI or what sort of camera.
I have a Blackberry Playbook, 64Gb storage, but it doesn't take external memory, ie SD card etc, and although I don't store that much on it, I have approx 30Gb left. I love the Playbook but there is so much speculation re the future of it. However, I'm sure the Playbook will be going for sometime yet. It is a good price but, being BB, the OS is a bit restricting although side-loading is useful.
So, my instinct would be to go for the Nexus. The specs are well identified and so you know what you are getting.
At the end of the day, you get what you pay for.
I'm sure others will be along and be able to advise you further.