Another way perhaps is to file a 'Y' flightplan, switching to VFR say 1nm from BIG. This would then make a 'legal' departure under IFR, and its been said before that Y and Z flightplans fall into the 'too difficult to charge' bucket as far as EC goes.
There are/were similar unfair payment regimes outside of aviation, look at when Railtrack was created, they charged train operators for track access in two bits, a fixed charge and a variable charge. The variable charge depended on how many trains you ran, your tonnage and route mileage, if you only ran part of the way for some reason you still paid the full whack. If you cancelled the train you still paid, so people had jobs deciding who cancelled what and who should pay etc.
The whole business of spreading the costs of ATC provision over the user base does not seem to have been particularly well or fairly thought out. Who chose 2 tonnes as a limit and why ?