Also another thing to add is that there are skins that it is understandable that you put them to make the general example of the prices but there are skins that are not worth the same as the others even if they have a certain tier. An example is the cosmic sorceress lulu skin (which only came out in a gacha years ago and its price was much higher to be able to get it. Currently it can be obtained in hextech), another example would be Redeemed Star Guardian Rakkan (which came out in a mission event, in which you had to pay the price of a normal epic skin from the store, that is, 990 wildcores to have access to the missions it contained, by completing them you earned tokens and with that you could redeem both the Rakan skin and the Redeemed Star Guardian Xayah skin. In short, the Redeemed Star Guardian skins of Xayah and Rakkan were not worth as much as the normal legendary ones, they were worth 990 wildcores and are currently only in hextech).
just a little correction: the skins tier are normal, epic, legendary, mythic, and in the future ultimate (its comming a ultimate skin for yone), so the normal skins dont have any color or gem on them, the EPIC ones got the purple gem on them, the LEGENDARY ones got the orange gem on them, the MYTHIC ones got the yellow gem on them (example: mythic chromas, special editions and prestige skins), for last the ULTIMATE will have a white gem on them. I just wanted to correct that because I saw that you made mistakes when differentiating the tiers, calling the epic skins legendary for example.
it varies between 1000 and 1500 Wild Cores. You can get different amounts of essences, like 8, 12, 16, 20, or even 1000, but the higher amounts are harder to get. We all hope for those 1000 essences 😭 so good luck, and I hope you get enough to buy the Lux skins you want!