[Pikeman]

Once the pig goes to the abbatoire and I want it butchered too how much will that cost.. And what do I get back please in terms of meat?

[The Woodsiders]

Think you need to speak to the abattoir, who I am sure will be happy to give you costs and advise as to the cuts you want.

[HappyHippy]

The kill charge will be around £20 per pig, plus whatever your butchery is. It varies - you can pay as little as £30 for a basic butcher done by the abattoir, right up to over £100 to get a good butcher to cut, pack & label. Things like having lots of sausages done or pork cured pushes the cost up a bit too.
Some butchers work on a price per pig and some on a price per kilo - ask around and see what they offer for their price (this can vary too, as can the quality & trustworthyness of the butcher who does the cutting)
Definately worth talking to the abattoir and/or local buchers now - come the end of the year they'll be really busy so aim to avoid December if possible 

I've attached a photo that should (hopefully) help when it comes to what you can get done with the carcass.
HTH
Karen

Edit: I've just noticed the photo doesn't enlarge very well - here's a link to a website where you'll be able to download the whole PDF - it's also got a handy guide about selling to the public too, scroll down to the bottom of the page 
http://porkforbutchers.bpex.org.uk/product/Business%20Advice/literature_hold.html

[Hassle]

Pikeman at the top of this forum is a list of abattoirs that people have graded if you are interested.

[Fowgill Farm]

Its worth noting that two pigs will yield approx 90-100kg (4 x 1/2pigs)of meat and make provision for freezing it or having customers to take it from you same day you get it back from the butchers.
You will need to check which days the abbattoir does private kills and either them or a butcher to do the cutting. And as previously advised if you plan to slaughter in the autumn get them booked in asap as its a very busy time of year for private kils & cuts.
HTh
mandy