I just posted about the Nokia Lumia 610 being priced at £15: http://wp.me/p1gHxJ-9uc.
Very good entry price and already it is possible to find cheaper. However, if you’re interested in the 610, why not go for 800 instead. Currently it can be bought for as little as £15.50 per month and you get a free Monster Nokia Purity Headset – worth between £126-182 depending on where you shop, if you pick it up today.
I believe the contract prices will remain the same. You may be limited on the the available minutes/text/data on similar contract prices when RRP of the phone is higher.
You’ll also note that this might be only for Orange. Total contract price is £372. The call/text/data bundle would be worth about £10/month so that’s potentially £132 over the 2 years. I’d want more data though.