I was bored again and decided to do this project again. Now that there are some new cards, the statistics have changed drastically.
1. There are a total of 198 unupgraded cards and 197 upgraded cards in existence.
How does this work? Well, there's no such thing as upgraded Malignant Cell.
Take out Ash | Ash and Malignant Cell and you have a total of 392 ownable/playable cards.
There are 25 rare cards. In this statistics page, I'm going to assume that the unupgraded rare cards cost 0, since they can't be bought anyways.
2. You need 7840 coins to buy a copy of every single card in the Bazaar. The most expensive card is Phase Dragon (109). The cheapest is obviously Pillars (6), and then Skeleton (7).
3. You need 50334 coins to buy 6 copies (15 for pillars and pendulums) of every single card.
4. You need extra 2101500 coins to upgrade every single one of the cards in 3.
5. In total, you need 2210008 coins to buy 12 copies (30 for pillars, pendulums), then upgrade half of them.
6. However, you'll win tons of cards and would sell the surplus. Assume that you gain 200k from that process. Then you still need 2 million coins to accomplish this great feat.