It is assembled over time, across sets, through trades, private sales, and the occasional find at pokemon card shows near me searches that lead you to a local event where someone has the exact promo you have been looking for
I had snapped up these Praetors during the prerelease windows (each at $800 or less), theorizing the unique art would make them quite desirable
And thank goodness
Another way to come across immersive cards is by earning them during certain events as achievements for reaching milestones, or they may pop up in the shop for a short period of time
When building a list of the most expensive, you have to refine your discussion to either include or exclude these three sets, as you would never make it to a consideration of the expansions or later traded cards without excluding these
You can put a land card onto the battlefield even if you've already played your land for the turn