9 Ball
If you watch airfares carefully for about 5 months before you want to fly in October you can get some great deals. Not sure where you are in the UK but do not limit yourself to only flying out of Heathrow or Gatwick, check Manchester too, you can even check Dublin which has some amazing deals. Also be prepared to check flying into several different airports this end, including Washington, Charlotte NC, Raleigh NC
My parents and Brother come over every other year and I think last year they flew into Atlanta for about $650 (400GBP) in October. Hotels are as cheap or as expensive as you want to make them from $45 (28GBP) to a couple of hundred a night, the best way is to look at Priceline and do your own bidding, or my brother quite often uses a site from your end ebookers. I am not too sure about what cheap hotels in the area are ok to stay at but someone on here must know.
If you are going to rent a car definately use one of the sites your end that includes everything partiularly regarding insurance. My Brother got caught this year with not using ebookers, but some other site and had to fork out an extra $300 on top of the car hire price when he got here. He says he will always use ebookers for car hire in the future. He paid around 450 GBP for 10 days car hire but was sure he could get that way down using ebookers next time
Entry Fee is currently $500 (310 GBP) you will find that everything else here is cheap compared to the UK especially food and petrol!! I guess if you do it on 1800-2000 GBP.
Hope that helps.