The solution to your question depends what cards you've got and their particular respective conditions.
Values of cards like twin lands, moxes, Force of Will, alongside powerful and collectible cards can be worth plenty a lot more than they were in 1997. Including, once I ended playing seriously around 2000, my endless Tundra cards had been really worth about $42 each. These days, that exact same card is really worth $300. Sweet!
The significant idea to know is that these valuable cards won't be reprinted. The demand grows due to the fact offer continues to be stagnant, reduced, and average quality diminishes. To put it simply, provided Magic the Gathering overall keeps growing, the values of the best older cards goes up. For those who have an old beat-up common card, then never expect it to follow similar value growth of better cards imprinted on top of that.
In the event that you would like to replicate my notably lucky instance of a 667percent ROI within the last 12 many years, there are maybe a few cards (12 or more) that may develop at that price. I can't speak to the persistence of the growth rate associated with value of each card, but I do know that we now have sites available to you that graph the values for the cards over time. If only I remained an enormous Magic nerd thus I could link you!