Hi,
Ferry prices have gone sky high in the last couple of years. The Ferry companies will tell you it is because they lost all the revenue when Duty free stopped. I think it's because the competition from the tunnel did not materialise due to the heavy debt to the banks.

Anyway the cheapest crossing I found this year was Norfolk Line Ferry Dover to Dunkerque, try their early riser crossings. If you use a Discounted ticket with any company pay cash because the companies are getting wise to the idea of booking a cheap return and not using the return. I know P and O will try and get you for the full fair if you use a credit card; it's in the small print. Also the discounts are better going UK to France rather than France to the UK, but don't try and get a discount ticket and not using the first half it won't work.
I don't hold to much hope of finding a friendly trucker most of the trailers will be sealed. You may find someone in a van but it' along shot.

If you go by plane from Germany try Berlin Air I got a 29 Euro ticket from them, but you are going to end up hear with no transport. http://www.airberlin.de/

I would expect to pay around 40 euros for bike and rider on an early morning ferry with Norfolk Line. Ask for the current deals.

Steve