For a moment I thought you were asking for precious gems that are generally not common (alternative)

Well firstly, in the bull run you sell and you dont buy. You buy during a bear run. Get that in your head for the moment.

Secondly, I dont consider any altcoin to be a "Gem" - they are not having any specific property that generates an inherent market demand but you can still try the top 10 altcoins from coingecko. But of course those are not under 1$.

So let me get this straight, the thing that you are looking for, possibly does not exist. Most altcoins that have performed well are way above 1$ and those who are still below that will never be coming up in price and buying them is like hitting yourself with an axe.