How many bloodpoints it takes to unlock every perk on all survivors and killers approximately?

Over 50 million, most likely.

I'd guess like 250 million or so. Per prestige level you want.

Survivors have 77 perks, with 3 tiers each. So 231 bubbles for each, assuming you are leveling every character to 40 first and then going for it. Say you get 40 bubbles on the way to level 40, which takes around 1 million BP. I think 40 is when you start getting 2 bubbles per level, and each web will take around 50k. So another 96~ 50k bloodwebs after that or 5 million BP.

So 6 million per character. 21 survivors, 126 million for survivors alone.

Killers have 69 perks, 3 tiers each. 207 bubbles. 1 millon BP to 40 with 40 bubbles done. So 167 bubbles after that, getting 2 per 50k bloodweb. About 84 50k bloodwebs or 4.2 million. So around 5.2 million per killer. 19 killers, or about 100 million for all the killers.

That's all just a rough estimate but bottom line, alot.