I'm afraid maybe high Age players (let's say from SAM on and higher) rather wish to neglet GE5 or delete city ...and "maybe" starting a "New game" ...
Others that go for GE L5 will mostly using up a lot of Goods by negotiate almost whole of GE5 ...
Since new players wish to get as soon as possible a few GB's build, they need also Goods and asking this to higher Age players :
1) almost nobody have "spare" Goods for sale for GB's for those "beginners" OR
2) they say "Goods are rare", you need to pay a lot of fp's for it!!
That's why I, being in SAM, can't even think about start playing GE5 : negotiating cost more than what I get back, so in some way worthless ... That's WHY I like to do the battles, even if I loose each battle almost all my units (or rogues), I don't care, Alcatraz can give me tons of units (if needed!). I care about Goods, I want always to have "spare" Goods so I can help fellow guildmates to get GB's constructed, etc ...
I'm not against negotiating, I just prefer to do the battles, but that's currently a real pain. I do not want it ALL EASY in this game, o no, not in a hundred years !
Being impossible is something else ... !
I hoped Inno Games DID something with all given suggestions and what I was hoping to see happen (just an idea which can, of course, be adjusted!!) :
1) GE5 get "scaled up" with the players's defender army boost ... so it STAY as a challenge, forever !
2) The Forgotten Temple: each time a player's Forgotten Temple become INactive after 28 days : it can be put INTO another fresh builded Forgotten Temple, which makes that second one even a bit "better" ! (makes Forgotten Temple L2, for example!) ... that way player's do not need to sell the inactive ones or using a "Store Building item" (which become more rare now) to sell in Antique D. ...