Well, I've tried 4 decks now with unupgraded cards. They are all a waste of time except perhaps mono-fire.
mark time - speed graboids, shriekers and earthquakes
unupgraded poison deck
speed green deck - adrenaline, frogs and cockatrices
speed red deck - dragons, fire bolts, lava golems (can do it mark fire or earth for pumping the golems)
My impression after throwing a couple of thousand electrum away is that most of the top 50 decks are much harder than level 5. My mostly unupgraded rainbow deck has much better success against level 5's. Unfortunately, I have yet to win a rare or upgraded card after a few hundred level 5's, so I though I'd try top 50 farming.
I've come to the conclusion that the decks that work well for farming T50 seem to all require rare and upgraded cards. I don't know how you got 6 pulverizers, but I don't have them. (Note: after several days of playing exclusively late night games I have yet to see a single rare farm deck. Not one. Ever. I know that it's up to the people if they want to do it and thanks for those who have done it in the past, but hey ... you all got your cards that way ... )
If I do L3's, I have to win over 750 games to upgrade one card. Getting 30 upgraded cards therefore requires 15000 games won. I suppose you don't need 30, but less than 20 is probably a waste of time and electrum.
There are two main problems with playing T50 decks with unupgraded cards, as I see it:
1) Almost all top 50 decks have 100% towers. Even if you win the coin toss, they usually have cards on the table before you get a chance to do anything. If you are playing a speed deck versus a speed deck, you lose. Thanks for playing. Would you like to visit your deck to see if you would like to improve your chances of winning? Oh, wait ... you dont' have any upgraded cards ... never mind.
2) Almost all top 50 decks are either speed (see 1 above) or based on denial (steal, destroy permanents, eat/destroy creatures) and putting up short term imprenetrable defenses (sundials, phase shields, bone walls) all strategies that are useful against false gods. They are also useful against the decks I've tried.
Thanks for the decks listed. I guess I'll try them out, but at this point, I've bought cards for 6 unupgraded decks to try what someone else has listed as the "ultimate" top50 unupgraded grinding deck (made by people who probably haven't really played a deck with a single upgraded card for months).
Meh. I guess this was a good game if you got in on the ground floor. I'm not sure I'm up for winning 25000 level 3 games at this point.