Yeah, when I realized I was within reach, I just built it anyway because it counted as a wonder for an era win, and a 1% or 5% or 50% or whatever chance of a gain was better than nothing. If someone else jumped above it didn't matter to me, it was the same as no gain at all as far as 1k was concerned.
Someone needs to work out the fame points per era for each rank. That information would be plenty useful for strategizing in general, and extremely useful especially for people aiming for the 1k achievement.