I'm in the process of this myself. My bank account was debited 188pounds earlier this week (I went for the extra pages and express delivery). Wish I'd popped home for a visit now and done it there! As you said, it's cheaper.
Just trying to find confirmation on the fees for renewing a UK passport. Nothing on their website unless you download the application pack (cost £15.99).
On the DirectGov website it says £77.50, but I'm sure it's about £150? Or is the the price for UK citizens to pay if living outside the UK and having to send their passport to Dusseldorf?
If this is the case, tempted to send all the paperwork to my parents and get them to send it to the relevant passport office in the UK if it saves me £70 or more.