The value of those blaster and mega boxes is almost entirely driven by Zion Williamson. If he does poorly or gets hurt again, the value of those boxes will go down dramatically. My personal opinion is that those boxes are not a good long-term investment. I would sell them over the next few weeks/month if you can do so for more than you paid for them. The other reason I recommend this is that the boxes you have are retail boxes, as opposed to hobby boxes. Hobby boxes have a greater concentration of high-end cards than the retail boxes.
As such, the value of retail boxes falls more quickly than hobby boxes. Odds are that Zion will not live up to the hype and the value of the boxes you have will fall below what you paid for them.

Now, if you REALLY want to invest in the Panini Prizm line, buy a couple of these hobby boxes: