I have budgeted £40k for my around the world trip, and I am pretty sure I will need every penny.
Depending on how many Pints you need a day, this should be plenty of money. We spent less during our 2 years and this included health insurance, flights, and immunizations.
Have you heard of Helpx.net? Check it out. It's free to join, but to get to the good stuff (Premier membership) it will cost you a few Euros. We paid 20 Euros for two years and it paid for itself with one stay. We house sat and did some work on a farm up in Scotland for about 2 weeks and loved it.
We were supposed to help restore an old ship over in Colchester too but that didn't work out so well.
Oh the good times we had! :-)