What will be the logical nested function if I wanted more then 1 condition to be met?

Good Afternoon!

I'm very new to excel and just started learning the basic functions.
I apologize if this is a silly query and thank you for any guidance provided:

Query 1:
What should the nested logical function be if I wanted to display “Highly Valuable” in the comments column
If either of the below conditions are met:
1. The release date is on or before December 31st, 1989 or
2. The sold-out status is Yes AND the percentage increase in value is at least 500% OR the Edition Size was less than 400.

And If I wanted an empty text string if the conditions are not met.

Query 2:
What should the conditional math and statistical functions be in a particular range to calculate the number of pieces, average estimate value, and total estimate value of the highly valuable pieces of artwork?

PS: Data file attached

Thank you so much MarvinP
"Edition Size" is the row E in the data file. Could you please help taking that into consideration as well, please.