Monies, pretty much.
Mora becomes an issue after a while.
Did 20 pulls, 2 4 stars weapons
Mora is definitely becoming a bit of a potential bottleneck.
I have my main team on Ascension 2, and from level 40 to 50 it costs ~100k using the puple EXP books. And you still want to upgrade talents, weapons and artefacts.
Though at the same time it's not really an issue for me yet, since my characters are plenty strong already and it doesn't hamper the exploration and questing at all. (I'm AR 27 and haven't even started the Liyue story, though I explored a good chunk of it and did a bunch of world quests there already).
If you want to reach the maximum power threshold asap things are going to get very expensive, but if you just upgrade a little every day it's fine. We'll see how long that lasts and when/if things are starting to get really painful.
In terms of pulls, I have 70something in the Venti banner. I think I'll do a few more to get another 4* and then maybe save the rest for another rate-up banner, as pity carries over.
I don't really want Venti, but I'd be happy with some of the other 5* characters you might get, but gambling on the 50% chance of not getting Venti and instead getting a character I want doesn't sound like too much of a winning strategy
(I've been mainly pulling on it because I like all of the featured 4* characters - I have C0 Fishl, C2 Barbara and C2 Xiangling in my main team - and wouldn't have minded Venti if I "luckily" pulled him early on, but now that I'm reaching the pity threshold holding out for a character I actually want is becoming more attractive).