Collector with Questions.

Hello everyone, I just started collecting again, and I was wondering whats the rarity(not price, like are they good to trade with) of the following Sandstorm foil cards

Aerodactyl, Typhlosion, Aggron, and Kabutops..

I also have a Mewtwo EX from R/S thats foil. I wasnt sure if ALL EX cards foil or what, and I didnt know if I should hold onto them or try to sell them..

Well there all pretty rare, and you should hang on to all of them. But.. The ones you should really hold onto is the Typholsion and the Mewtwo.

Here's the rarity scheme for RS and SS. One Rare and one Reverse Holographic card are in each pack. The RH card can be ANY card except for the EX's. ex's and regular holos are weighted the same, replace a Common card in the pack, and come about 1 in every 3 packs. The ratio of ex to regular holo within that ratio of packs is about 1 ex for every 2 holos. Do the math yourself.

Also, Typh ex is pretty pathetic now that Blaze ex is out. All the cards that you mentioned are ex's, and all ex's have that holographic type treatment.