Wow! $2000 for a set! I had no idea custom sets of Legos were so pricey, even at 72 tiles that seems like a lot, given that the blocks used are pretty basic.
By far the worst is the shipping. I designed a 20 piece micro star destroyer, pieces cost $3, shipping is $60.
So I did a bulk order from Toy Brick Brigade ... still waiting for them to turn up (the postage time was ~2 weeks and it hasn't been 2 weeks yet).
I believe the cheapest way to get specific bricks is probably to regularly go into a Lego retail store where they have a pick a brick wall and wait till they have what you want and then pounce. :D
If they never put up the brick/colour combo you want on the wall, or there isn't one of those near you, or you don't live in a country with those, then you are SOOL.
From Toy Brick, the nominal price per brick was something like 4c-27c. For minifigs, the sky is the limit. I can't believe people pay big $$ for those. Oh sure, Han Solo or R2D2 or Darth Vader or Yoda maybe I would understand, but some random-ass Jedi that never even appeared in the movies going for $30? I don't see it.
The other problems with buying Lego from Lego is piece selection and colour. I couldn't get any of the 2436 bracket pieces in the right colour, and I could get 43719's at all even though I know they come in at least one recent set.
Ideally you probably don't want to be paying more than about 8c per piece (or 11-12c for the Ockers in the audience).
One of the ways I found to get around the shipping problem was to order the Lego hardbound books from the Book Depository in the UK, that was an interesting exercise, since by piece count most of them are reasonable, and they come with minifigs too. The Pirate one has about 140 pieces which isn't enough to do anything interesting with, but the general look and feel of that kit would actually integrate well with the castle/medieval style sets I think. The technic one looks to be by far the cheapest way to get the technic pieces (mainly gears and bricks with holes in them).
The Star Wars one has 240 pieces, to make 2 models, but it has four scenarios each with 2 different models (the 'story' is that a clone trooper and a separatist droid are fighting, and the models are for different vehicles from their armies). So in terms of value for money that rates extremely highly in my book (sic). I bought an extra one in case I was feeling generous towards my nephews, but may actually keep it for me :D
For minifigs, the pack with the 4 Mandoralians is the only one I consider a must have. You may not be familiar with Mandoralians, but that was where Boba Fett got his cool looking armour. So you get the cool armour without the whole embarrassing 'died from falling into a pitcher plant like a total noob' thing. :D
which is a more reasonable price per minifig, but you will get some you don't like.
For building spaceships and/or aircraft, the lego midi scale star destroyer is brilliant. It is basically four massive wings, and each wing is made up of many other wing pieces.
It is also quite reasonably priced ~$30USD, ~$60AUD (never mind that 1AUD = 1USD)
Very nice. I'm not familiar with the game, but I spent a couple of days in the real Carcassonne and it is amazing. If you can find a hotel room in the city walls it is well worth it.
