Careful. Once you start learning about them they become more interesting. Fear gives way to even more curiosity and before you know it you have a room full of thousands of spiders. That's what happened to me!

As for the average eggsac it depends on the species. Some have a ton of spiderlings but the spiderlings are incredibly small (e.g., the genera Brachypelma, Nhandu, Acanthoscurria). Another trend is to have relatively few babies (50-100) but they're much larger (e.g., Megaphobema, Theraphosa, Xenesthis). There are a number that fall in between these as well. Our Poecilotheria, Pterinochilus, and Heteroscodra eggsacs are typically between 100 and 200 slings. So it just depends on the species.