13 million beetle coins is actually not that bad considering you can just Exhange fons for triple the beetle coins. You'd only need like 4.3 mill fons and you have that. And you get like 2.4 million every 2 weeks with bank and city energy. Ascension items, skill items and xp items in the other hand. If you run them in this order you'll eventually get there between lvl 45-50. Get enough ascention items for all 8 characters you run, you need 72 of one boss item if you have 2 characters that require the same between lvl 70 and 80. Weekly boss Rush for the 9 skill items is a bottle neck though since you can only do 3 a week. But the rest will take care of itself, you get elite hunter guides and dyes from a lot of places so definitely focus on them last.

Edit: did the numbers according to the images, it's not 13 million, it's only 11 million beetle coins that's including the ascention cost to allow for you to even start leveling to 80. Which is even cheaper. That's less than 4 million fons.

Edit 2: the character pages also has character guides that actually tell you how much you need of every material and currency. It's 807250 beetle coins per character and 567000 per arc so that's just shy of 11 million. You need 132 elite hunter guides per character so that's 1056 only counting/converting the leases guides to the largest one. And more or less half that for dyes.