Depends on many factors... 10 Stickers usually are about 7 or 8 grams, but depends on size and paper weight (WC stickers are usually the lighter)
Packets might be about 5 or 6 grams (usually 1g per sticker in average)
Empty albums from the most known competitions probably are around 200/250g... Complete can reach around 600g (stickers stuck in he album) or about 800g per album + set.
When using cardboard, you're adding more weight of course... So you need to make a quick analysis: what I'll send really need to be very protected? If so, what is the best option? And how can I send without adding too much weight and pay more because of it? That's why a few years ago, I bought an electronic scale from some HK seller (cost me about 6 dollars, I think), that way I can check if my layer of protection is going to make me pay more... For instance, when sending a single packet, I don't want to surpass the 20g limit for small letters here... I also don't want the small letter to be bulky, so thick cardboard is not an option... Therefore, I chose that malleable cardboard, because it's still protect very well and it's lighter.