I just found out that when you upgrade your wonder and use boosted goods it takes away from you r bonus. Thats just plain DUMB! Why didnt you have us just use the relics that we had no use for? Every update shows me how these developers dont use their brains at all.
Some of us have delayed the Elven/Human Wonders for this reason. Building the first two Wonders provides minimal benefit - unless your city really really needs the culture bonus from the Lighthouse.
Getting through the Dwarven level significantly boosts your goods output. The faster you move through, the sooner you get to the increased goods. More goods equals more ability to buy KP. So, use your hard-to-gain KP (the hourly kind) to move through Dwarven...then once you're producing lots of goods, use them to purchase KP much more quickly. Overall, delaying the Elven/Human wonders means you can likely get all your Wonders completed more quickly (should you decide to do those first two at all).
Also, during the lengthy Dwarven section, you can use any KP generated by waiting for copper/granite to win rune shards from other wonders. Then, when you're ready to build with additional goods power, you have shards and KP and they pop up pretty quickly.
And about the relics...building the Lighthouse will slow your progress because you'll have fewer and fewer goods. I felt it better to keep all my goods, gain the full Mountain Hall boost (I'm Level 7 now, with a 53% boost extra) and then I'll bite the bullet and go backwards in my goods production. After I've finished every available upgrade and stocked my Main Hall...