As an aside, I worked as a money broker during the 80's. When the market was quiet it was quite common to 'trade' other items. I remember my boss receiving delivery of 5,000 dildos, 15,000 cream eggs etc. The most expensive item I personally traded was a bucket of rhino poo @ about £2500. A few beers and £50 secured delivery from a keeper at London Zoo. The tube ride was however a bit awkward.