You can buy LEGO in bulk at any official LEGO store. It is called the PAB (Pick-A-Brick) Wall. They will sell them to you buy the cup, or if you need really large quantities, you can also ask them for full boxes. Keep in mind that the selection changes seasonally, and you will not be the only seller who buys parts this way, so there will be competition.
I feel I need to represent the Classic Town and Train fans with the following sets:
6399 Airport Shuttle
Bricklink items for sale
The only town monorail released by Lego and one of only a hand full of monorail sets in total.
As is the case with many classic sets that are hard to find 100% complete, it includes many stickers that easily become lost or worn ...
Not sure about several years, but Brickpicker covers one full year. Here are the stats for the Green Grocer, for example:
Or the ones for the UCS Millenium Falcon:
And so on, you get the idea. They have more and other stats, too — e.g. the following quick overview for every set:
They pull their data from eBay, through some third-...
The LEGO aftermarket is changing all the time and there are no defined rules on how a set will appreciate. Over at http://www.brickpicker.com you will find an entire website (plus forum) dedicated to investing in LEGO sets.
The post-EOL rise in price of a set is driven by many factors, some of which are:
If a set is only available for a ...
Trading in LEGO isn't an easy way to make a lot of money. The margins are much smaller than they were, and you'll face stiff competition. That said, it is possible to make a profit if you do your research and you're willing to put the effort in. Few of us make a fortune, but many of us make enough to fund the odd purchase for our own collections.
To trade ...
There is a website that tracks price changes on Amazon, Bricklink and E-bay in order to try to compile an index. It has an interesting page called top retired sets, ranking sets by gain compared to initial purchase price.
At the time of this writing it lists 6166-1 (a big tub of LEGO) as number one with 65% gain, and 7200-1 (final duel) as number two with ...
I'm not familiar with any tools that do this with eBay or Bricklink price histories. I'm pretty sure that Bricklink removes all data older than 6 months, so if this information is available, it would have to come from a third party who scraped it from the site.
I have used a tool called Tracktor to look at Amazon price histories for LEGO sets. Sadly, this ...
There are now loads of sets which could be considered to be the most valuable. Here is a list of my choices
10179 UCS Millenium Falcon
10182 Cafe Corner
10196 Grand Carousel
10184 Town Plan
Chrome Gold C3PO (only 100 made)
10189 Taj Mahal
5004590 Bat-Pod (only 1000 worldwide and will surely increase in value tremendously)
This list is only my ...
I must say, a very valuable one would be the exclusive Maersk container ship. the original 2004 set (not the 2011 reissue!) is worth a lot of money, considering they only made a handful. other than that, the Unitron Monorail can go for quite a bit MISB (Mint In Sealed Box) nowadays.