Don't be browbeaten into joining the Union by a booklet!!
I'll say it loud and clear:
The Oxford Union membership drive is deliberately designed to make people join who they know will gain no benefit from it.
There are loads of impressive speakers everywhere at Oxford; EAS, for example, have probably had as many heads of state visit as the Union since 1990 and joining them is about £10. Getting to see MP's and academics and all that is a pile of piss and can be done for free. Arguably the experience's better at smaller societies coz you get more interaction. If you really want to see a speaker you can do so even if you're not a member for just £3 and contrary to what people say by Hilary term even the really big speakers don't fill the hall. FW De Klerk, the South African President who oversaw the dismantling of the Apartheid regime, spoke to an empty gallery, I'm pretty sure. That can fit 100 people easy.
The Union is amazing - but so is most of the rest of Oxford, and the rest of Oxford isn't nearly so expensive.
If you're enthuasiastic about debating and are going to go very frequently and speak, and are interested in the social scene of the Union and will make use of the libraries and the cheap pints and snooker tables and DVD library, then it is well worth it. The very fact that you're equivocating shows you're not sure that you do, so why are you getting ready to throw away £150? Wait till you get here, have a closer look. After all you have three weeks before the price even goes up and even then it's only £14.
Why d'you think, by the way, they have the cheaper initial offer? It's to pressure people into signing up who, had they not joined initially, would've realised there's so much on at Oxford that the Union isn't worth it.