You should buy the Masterwork Research: Wish Granted Ticket in Pokemon GO if you want to catch the shiny version of Jirachi.
This is because the Wish Granted Masterwork Research is the only way to catch shiny Jirachi in Pokemon GO.
If you don’t want a shiny Jirachi, then this paid Research isn’t worth buying.
In addition to shiny Jirachi, the Wish Granted Research includes rewards like 20 Jirachi Candy as well as 10 Candy for Groudon, Kyogre, and Rayquaza. This Candy is especially useful as Primal Groudon, and Primal Kyogre are now available in Pokemon GO.
However, you will need to play Pokemon GO many days in a row to finish certain tasks and earn all the rewards. In fact, almost all of the Research Tasks in Wish Granted are pretty time-consuming, and the whole story will likely take a couple of months to complete!
If you’re undecided, find out whether you should buy the Masterwork Research: Wish Granted in Pokemon GO.
If you don’t feel like you could complete all of the Tasks, it is definitely worth skipping this Masterwork research. This is especially the case as there are great shiny Legendary Pokemon available to catch in the game right now:

How Much Does Masterwork Research: Wish Granted Cost in Pokemon GO?
The ticket for the Masterwork Research: Wish Granted Costs $4.99, £4.99, or local currency equivalent in the Pokemon GO in-game item shop. This makes it a mid-priced event ticket by Pokemon GO standards.
Considering how long it takes to complete the research, it is a decent purchase for hardcore Pokemon GO players.
You can also gift this ticket to in-game friends by selecting the Gift button when you purchase it.
While this Masterwork Research is all about Jirachi, there are plenty more Mythical Pokemon in the game. Here’s how to catch every Mythical Pokemon in Pokemon GO!