I'm in West Lothian - the only one I know the price of is £9, for about an hour's walk...but by the time you add in collecting them and getting them settled back in the house it's closer to 2 hours of company.
In Berkshire a half hour walk for one dog is about £8/9 - I think it is more for two dogs though not double - sometimes my dog walker just comes to walk mine round the block for 10 mins or so and I pay a fiver for that. Bargain.
I'm South West - my two go to daycare once a week (£33 for both of them, picked up and dropped off, about a 7 hour day for them). The same people also do dog walks at £8 per dog for a private walk or £6 per dog for group walks (up to 4 dogs). That's an hour of walking, so as tabulahrasa said nearer 2 hours with the collection / drop off time.
I work four mornings and placed an advert locally, we found a lovely retired lady who looks after him at her house with her own little dog and though she doesnt walk him, she does have a large garden so he plays out in that.
The only time he ever pulls on his lead is when we are walking up her path
I'm in Surrey and have just found a brilliant lady to have the devil dog occasionally. She charges £12 for a whole day, 8 - 6. She takes her out walking twice, lets devil dog run around the garden with the other dogs and feeds her. Devil dog comes home knackered! Marvellous!