People are selling pieces for pretty high prices on Excalibur. Originally listing were in the 5 million range, but have reduced quite a bit. Still, some pieces are 2.5 million+ even thought the parts required to make them aren't really that expensive.

For every piece that I have wanted, I have just collected (bought) the materials, and made a Party Finder asking for a specialist to craft (and offered a tip, of course). I got pretty fast responses from some very helpful individuals (under 10 minutes). This way costs me about 1/4 the price listed to buy it off the MB.