As far as i know - you cant really make that using Variants. You could make specific variant like 'pack of 10 products', but that way you couldnt track inventory.
If i understand correctly then you could look into Shopify discount type 'Buy X Get Y'.
Essentially you can set it as if customer buys 9 of product A and get discount for 1 of Product A. That way customer can buy 10 Product A with discounted price. Only downside would be that customer would need to enter discount code at checkout.
You can look for apps that automatically applies discount code 🙂