Ah, apologies Pedro, you are right. For us it seemed easy up to Quest 13 because we are months into the game. Our current amount of Viagra is over 63k, so that's a nice buffer. (Our highest was in the 220k we think, but then we got a few Epic cards to level 24 and also the Legendary Rider was finally up to 8 cards, and we are not as diligent in the adventure battles anymore so we haven't regained it.)
The speedy research was possible for us since we got a few examples of those speedboost items in June and August with mail from the developpers, and we never had a reason to use them until this event.
Thanks all for confirming, we just wondered if we were missing something. Like BitchPudding said, the 17500 task seems a bit silly when all we can use is 5k...