The DT produces a single "random" good of any age you have been in per aid and the number of times it gives a single random good is dependent on the level, so while your in SAM age collecting Iron Aged, ME or LMA goods etc etc i am collecting SAM goods, for an equal space (6x5) i can have 5 sleigh builders up giving me 75 SAM goods a day while you would need a L46 DT just to get 75 random goods (assuming you aid 75 players).
As far as it needing a one up that just makes it much more useful because then on the day we start the new age i can be gaining 75 goods of that new age while your DT might give you 4 of the next age to SAM (assuming 75/17 ages).
Plus since you spent 1875 TE goods to get it i suspect you will never actually get enough goods back to pay those costs, plus the 59,185 FP to get it to L46 (of course if in top guild with a 1.9 boost for it it reduces to only 12237 FP)
Sorry but its totally useless and unless to any serious player, but its ok if you happy with a pretty building.
Its only real purpose is to give a new player goods from across 17 ages which they can accumulate and try to trade down to the age they are in, but its TE so will be difficult to get for a new player to get the BP's and might cost even more FP for a TE goods pack from another player. so maybe another 600 FP and assuming you have the BP's the new IA player can build it and get some benefit, but even that benefit starts to go once the player starts to catch up the ages and the DT starts to provide goods from ages long since past and not required - so it becomes useless.
For a great read try this thread
https://forum.en.forgeofempires.com...sing-the-real-value-of-great-buildings.11260/
while its old theres a great deal of debate on whats a good GB and what is not and it does make you think.
My thought is never build a GB and hence invest FP in it if you will later delete it, just a massive waste of Goods and FP.
The other thought is do you have a better GB to spend your limited FP in? if so then do not build that new GB.