I think the idea is that Patrick has provided three localised volunteers to build in certain areas of the world: the UK, Europe, and the US. Jon is UK, I (Rob Schofield) am in Europe, and Mark Lord is in the US.

If you choose to build it yourself, Patrick will mail it to you. End of story. If you want someone to build it for you, you click on your "local" constructor and Patrick will mail it directly to the builder. You then have the additional construction costs to pay, plus the postage from the builder. The idea is to choose a local builder in order to minimise your postage costs from the builder. So, if you are in the US, you would not (for example) want to choose me or Jon due to customs issues, and the cost of postage from Europe to the US. However, if you are in Belgium (for example) you would choose me (or Jon if he was cheaper ) and the postal costs are lower, less hassle overall.