Redmafia, I must agree with Pwnator:
T50 is most definitely worth your time and not just in terms of rare cards, electrum too.
Here is a deck I would still suggest for T50 pawnage:
http://elementscommunity.org/forum/index.php/topic,5618.msg63468#msg63468(If you get the feeling you are not meeting ~50% rainbow decks in T50 but only those stupid frogs,
Hope-decks and so on ... trade in the blackholes for a couple unstoppables, poison, flesh-spider, deflagration, blue crawler, pegasus, another graboid ... just fiddle around with it a bit.)
As you can see, you will need 6 upgraded supernovas for any deck like this and some Quantum Towers
help a lot too, which answers your question which cards to upgrade first.Now the uncontested FG deck right now is this, I would say:
http://elementscommunity.org/forum/index.php/topic,6546.0.html(raw build; trade towers and fractals for shards of gratitude to increase savety/decrease speed)
However, there isn't that much else you can do with those tons of upgraded cards until your
collection is more respectable.
This goes pretty much for any specialty card at first, so whatever you do:
Do not upgrade any special cards like Immolation, Photon, Fractal, Basilik Blood, critters in large numbers... !Going for supernovas and QTs first will open a world of opportunities against FGs, T50 and PvP.
For example, you can start building a FG-deck like these two classics:
http://elementscommunity.org/forum/index.php/topic,1748.0.htmlhttp://elementscommunity.org/forum/index.php/topic,4212.0.htmlWhich will then lead over fluently to highly promising new FG approaches like:
http://elementscommunity.org/forum/index.php/topic,13863.0.htmlWhich each deck you are building, there will be less cards you need to upgrade to make it
and with your supernovas and quantum towers you will always have the basics ready.
Also, whenever you DO win an upped card from the FGs there is a good chance that it will
fit nicely into your rainbow-deck ... few cards from each element are just what speed-rainbow is about.