The 3rd kind of value is sentimental value. I think you will take good care of them-- but most important, wear them!
And restring them periodically. Silk deteriorates as it gets old, or wet, or absorbs body oils and environmental grime.
Many of us restring our own pearls. You can see videos and tutorials on the Lowly Beaders Club, if you want to give it a try. It's not hard (especially with new synthetic threads) and it saves money doing it yourself.
Another invaluable resource which I recommend to just about everyone is Renee Newman's Pearl Buying Guide, which she updates periodically to reflect changes in the pearling industry and the kind of pearls that are available. The most recent edition is the 6th, from 2017. It's beautifully illustrated and full of great information.