I can only encourage you to read all the stickies, all you need to know is in there. So, tip number one is: Read a lot. Afterwards, you will need a lot of patience and time. This isn't like doing a paper flyer, where you have a rough look at the building instructions, then rush through it and still get it to fly.
I'd recommend getting the cardboard first, 200g/m² is ok, a little stronger might be better, but make sure your printer can take it. I'd also recommend getting a cutting mat in A3 format, that helps a lot. What kind of knive to use is your choice, I like the scalpel-type (like X-Acto in the US), but some people go with utility knives or scissors. You'll also need replacement blades, since a dull one will first ripple and then rip the paper. To glue them together, I'd recommend liquid super glue in some kind of small plastic bottle with a precise tip.
The rest of the materials (resin, bondo, paint, tools) you can buy later, pepping all the parts will take some time anyways.
Concerning the price... I would NEVER just convert the prices given here to another currency. As I wrote yesterday, I was stunned when I saw the price tags at our local hardware store. They are nothing like the prices in the US, even if you just look at the pure numerical value without concern for the currency.
You also have to take into consideration that you may need to do a piece twice for a whole bunch of reasons and that you may need tools you don't have. Those aren't consumed by the building process, but they still add a considerable amount to the price of your first suit.
