As I noticed many people complained about the current state of TR/CA pathfinder, I decided to share my personal experience with the build. Disclaimer: I am a bad player so feel free to correct me

I knew I couldn't play a lot during the first week, so my focus was farming currency during the first weekend and investing in items that will eventually appreciate. Therefore, the investments I have made in my build are minimal.

Key steps: I leveled as PC until about T8 maps after which I swapped to a 5 link +2 gems bow (<5c).

You need vaal CA for single target combined with withering step (not on left click) and withering touch totems on TR (4L). This should be enough to do T12 maps comfortably. Chaos dot multi on every item you can fit it on is an absolute must; you really feel the damage difference. Until this point your budget should still be under 20c.

Next upgrade is Asenath's Mark (Soulrend, GMP, Efficacy, Despair). This boosts your clear greatly and allows you to drop arrow nova in favor of slower proj. Your curse is autocasted so one less button to press. IMO this is a must and not using it takes all the fun from the build.

Around this time I also spent like 120c for a +3 6L bow (no chaos dot multi, those are more expensive). By now you're able to do T14 - T15 comfortably. Vaaled T16 with eater influence and difficult mods can take a while longer but you should be able to farm efficiently in red maps.

By the way I'm almost capped chaos res without even trying, could probably cap it within a 10c budget but passive tree carried this one. I also have enlighten to fit 3 auras but this isn't really needed, just get grace and swap between determination and malevolence depending on what you need.

Any advice is more than welcome, I'm learning on the go :-)

TLDR: Caustic arrow is very good for low-mid investment levels. Here's my lv 91 pob with about 1-2 divines invested. https://pastebin.com/Sxxu4fcz