The Isis Adventure

So here it is in 2013, I'm thinking of starting off with the Isis since it the first in the set.

1) Is it really worth my time to try and get to a pyramid or are they all pretty much down to the silver coins? I think I read somewhere after the gold coin is claimed you don't need to crack the riddle to get the silver coin.

2) If I move on to the Ramisis, does that puzzle have a different set of pyramids to get, or is it all one set and any puzzle can get to any pyramid?

3) Will the prize at the pyramid (either real or virtual) be worth enough to bank roll the next puzzle in the series?

Personally I haven't gone after any Pyramids, but I'm lead to believe that there are a few with gold coins in them still out there - don't know about the riddle after the gold coin is claimed though.

The Ramisis has Sphinxes rather than Pyramids - but if you have both an Isis and Ramisis solved you can take part in the Platinum Pyramid hunt $5000 prize, which should bankroll any puzzle purchases you can think of!