An pack for 4-6$ that resets the population on your current map and adds new species to that maps roster one pack should include about 10 species and may be a bit of storyline an idea could be new map once a year and new map expansion pack twice a year.
I will make a concept for every map I think could really use it.
https://discord.com/channels/393040947006406657/1248312931339468832
https://discord.com/channels/393040947006406657/1248316858931875910
https://discord.com/channels/393040947006406657/1248319376717779058
https://discord.com/channels/393040947006406657/1248321894684426391