Have you ever heard of the ex series? Ya know, with the first ex cards (before EX).
Well, they contain a secret rare Mew, a shiny Charizard, Rayquaza, and Celebi already, and the prices for those now are practically set in stone (there's very little variation).
Speaking of prices, let's go over them!
Secret Rare Mew is no more like $10, probably like $5 (I have to double check, but it should be a good guess).
Shiny Charizard (Charizard Gold Star) is about $50-$60 NM+.
Shiny Rayquaza (Rayquaza Gold Star) is about $90-$100 NM+. The reason this card is so expensive though, is not only because the pull rates for ex Deoxys (the set it came in) were like one Gold Star every two boxes, but Rayquaza Gold Star was made wrong or something and almost every card out there experiences peeling on the front edges, which ruins it's NM+ condition, so NM+ cards go for rather high prices (like $90 or more) while less that NM cards still go for a good amount (because of the extreme rarity). Now, you may be saying "Well SR Rayquaza also has some hard pull rates, so shouldn't it's value be just as high?" The answer is no. Why? Because if you look at the print records of both cards, you'll see that there are
way more SR Rayquazas printed than Rayquaza Gold Stars because Pokemon cards are a lot more popular then they were back then.
Shiny Celebi (Celebi Gold Star) is like a $20-$25 card when NM+.
And the popularity of a card does add to the value, but (at least in this case) not enough to keep a card above $50 (or even $30 for that matter). When cards first come out, it is primarily the playability that drives the price up (that's why Darkrai EX and like cards fetched like $80+). However, popularity (because of the Pokemon and the new set) adds to the first prices of cards. This can be seen with every new EX card that comes out - although some are more playable than others, when they first come out, almost all of them have a "high" value (there values were higher than they are now). Both of those reasons, along with the crazy pull rates for the card, are what drove SR Rayquaza to be a $100 card. The card was though to be rather playable (although now it is only mildly playable), it was a shiny Rayquaza, which are always popular, and then it was very hard to pull, which makes it rare and hard to get a hold of. These 3 factors (popularity, playability, and rarity) combined can make any card very high in value, and each factor contributes value to cards (so a card with at least 1 will be worth more than a card with none/less).
But then there are factors that counter those 3 mentioned above. One of these is time. As time goes on after a new set is released, players build new strategies with the new cards, and the truly playable cards emerge. With SR Rayquaza, players realized the card wasn't as playable as thought, so less people wanted it, the demand dropped, and the price fell with it. A major counter-factor is also the non-ultra rare print or reprint. Almost all playable cards have/get a reprint. Darkrai EX got a reprint with the tin promos, and SR Rayquaza got a non-ultra rare print with the release of the Dragon Vault box. Other Ultra Rares released in sets sometimes tend to already have non-ultra rare prints in the set, which kicks the value of the Ultra Rare down when playability is a factor in the pricing (as time goes on, playability becomes less and less a factor, especially when a set is rotated out).
Oh, and also, you cannot use the pack cost times the pull rates to estimate a card value (like the ~$2,000 pack price you quoted for SR Rayquaza). This is because not everyone spends ~$2,000 to get their SR Rayquaza. Thousands of packs get opened, and out of those thousands, an appropriate ratio of SR Rayquaza's get pulled. The reason this is important is that I can go buy 2 packs from Walmart for under $10, and pull a SR Rayquaza. That doesn't mean I'm gonna go sell it for hundreds of dollars because the card, based on its pull rates, would be expensive to pull. You see what I mean? Pull Rates are not specific to each person. I am not going to have to open 432 packs to get a SR Rayqauza - I might only have to open a few, or a handful. Because the pull rates vary per person, the price is not some ridiculously high number that reflects the cost of packs needed to pull it based on pull rates.
PS: I say all of this to contribute to the information of whoever decides to read it. I in no way meant to sound/be rude, offensive, or mean by typing anything above.