If you seriously think a Blackberry Playbook is "something similar" to an iPad, you need to look a lot closer.
If the build-quality, the OS, responsiveness, app library, accessory market, usability etc. etc. are all things that don't matter to you, then the iPad is not for you. Many people are willing to pay a bit more for those things. Some people are content with cheap, inferior products that are no longer supported and nobody else has.
There is a very good reason why Playbooks are being dumped at £129. Nobody wants them, and RIM themselves are in the dumper and desperately trying to offload devices they can't sell on people who don't know any better, and think they're buying 'a cheap iPad'.