QUOTE(chew_loong @ Mar 17 2014, 01:01 AM)
For Modulars or UCS sets, chasing the few previous current sets; after a while its not worth it to chase the old. The prices are over-aggregated and most of the time over inflated. Besides being a good "Show and Tell" piece for elite few, for most of us is very hard to justify the cost to acquire it.
Anyway, with the re-released versions or new sets is always much improved with more details. Might as well shoot for those current new sets. Just have to be patient, scout around and see what comes along.
I could not agree more.

Retired sets are gone, and chasing them will cost AFOLs a bomb... but they will always be some willing buyers who are completist and willing to pay those inflated prices. It comes down to simple economics of demand and supply.
When it comes to Lego re-releasing retired sets, I don't think they have ever done so or ever will (but I stand to be corrected). From a business point of view, they can sell more sets if they release a new and improved version/design, like what happened with some of the Star Wars vehicles and spaceships (X-Wing, Falcon and now Sandcrawler). If they re-released the exact same 7191 UCS X-wing or 10144 Sandcrawler, the thousands who already have them won't be buying the same set again. Yes, there will be many new AFOLs who missed the original release and will want these sets, but at the same time a new design will be more sellable to both old and new AFOLs.
As for non-licensed exclusives like modulars, trains, ships, etc... the same logic applies, Lego is unlikely to release an old design that has already sold thousands. In fact, the possibilities are endless here as they are not bound by an actual movie or product, and there is so much more new creations they can release and sell compared to a re-issued Green Grocer, Emerald Night, Imperial Flagship or Taj Mahal. But we AFOLs who missed out on some of these retiured iconic sets and are not willing to splash the cash for them in the inflated resale market, can still wish... maybe Lego will prove me wrong and make my dreams come true someday.