Just thought I´d continue the Scottish theme!
These guys have a fair bit of info on their website which you might find useful.
I also have some of my initial budget costs on my own website for my trip:
For my own trip, so far I really haven´t added anything up yet (too scared) but from memory, our daily expenses in South America consisits of roughly:
Accomodation- Matrimonial room with/out bathroom is generally around 10GBPs, sometimes less, sometimes more. I´m travelling with my girlfriend so our accommodation cost is shared. If you camp (we did a lot in Arg & Chile, none so far in Bolivia & Peru), its about 3-5GBPs, again sometimes less, sometimes more. Or you can free camp the odd night like we have done if you find a nice spot.
Food- When camping, we cooked a lot ourselves. Also, most hostels will have some cooking facilities but its nice to eat out (and sometimes it isn´t!). Here in Peru, you can get pretty filling (if very samey) local food for less than 1GBP. Just eat where the locals do rather than the tourist places on main Plaza´s etc.
Fuel- Depends on how much you ride per day. (I have a note of most of the fuel prices from Argentina, Chile, Bolivia and Peru if you´re interested). Here in Peru, its about 13 Soles per Gallon- I´m confused, I´m a litres kind of guy! Yesterday I got 10L of questionable quality 84 octane fuel out of a bucket in the sticks for 30 Soles but then I was desperate. There are about 6 Soles to the UK pound I think.
Country- Chile has been the most expensive (very similar to UK prices in some places, less in others), followed by Peru, Argentina and Bolivia (though we didn´t find Bolivia quite as cheap as we´d thought).
Shipping- I shipped my GS1150 from London to Buenos Aires in October. I reckon it cost more or less 750-800GBPs all in, one way. The crating is one of the most expensive elements (about 300GBPs, the shipping itself was only 200GBPs) so if you can get a second hand one or make it yourself, do it. That price also included the clearance costs plus the hired help of the wonderful Sandra at Dakar Motos in BA who helped us get our bikes out.
Bike- I´m not sure I´d recommend taking a BMW to South America as its been a total pain to get parts for. Don´t get me wrong, its been fantastic, pretty much trouble free really and has gone over terrain I never thought it would. People often complain their bike runs rough at high altitude or with crap fuel but my GS hasn´t even noticed yet (and no, it doesn´t have that expensive chip thingy) Its just way too heavy for off road but saying that, I didn´t drop my bike once on that stuff in Bolivia so there! The only dealership where I got a very expensive oil filter was in Mendoza. I also had someone replace my forkseals for about 40quid, only for them to blow a few days later. I did them myself and they´re fine now. Tyres for it are also very difficult to find, but generally you´ll get a Pirelli MT60 and thats you´re lot. My girlfriends KLR 650 has had its moments but most of those could have been avoided with a little more prep before leaving! Its been great though and you´ll get parts for it no problem, pretty much anywhere and its easy to work on. Don´t bother with huge tanks either, if you need more fuel like we did on stretches in Bolivia, just carry some in a plastic container.
Clothes- Just bring the minimum. You really don´t need much and layering is the answer to the temperature variations. 2 or 3 t-shirts, one long & short sleaved shirt, a micro fleece, couple of pairs of cargo trousers (one with zip off legs), etc. Its a pain to keep taking out linings etc but theres no one set of bike clothing that will cover everything. My HG cruise suit has been great as it has vents for the hot weather, linings, zip-off storm collar and kidney section. Anything you wear will feel too hot in Lima traffic for example but once you are out on the open road, its great. When i come in to a town on a really hot day, I now generally stick my jacket under my cargo net behind me though it doesn´t really offer any protection.
Anyway I reckon you could do it for 10-15GBPs a day, excluding shipping, flights, and dreaded bike maintenance (specifically tyres!) but all countries are different so its difficult to get a definite figure.
Before I left, a friend from the HUBB told me he did his 10month long trips on about $25 a day which included all shipping etc. It also helps to have a property which you can rent out, though I feel I´m just about to get stung for tax on that!
Ok, thats your lot. Hope that´s of some use.