TLDR: the current respec costs are low enough to allow you to make relatively large changes to your character for a reasonable amount of gold. They are high enough to avoid all the (many) pitfalls that come with cheap/easy respeccing.
Intro
I was reading a lot of complaints on Reddit about the the cost of respeccing skills being too high. Granted, this was exacerbated because (in early access) the devs made some major changes to skills which prompted people to (incorrectly) believe they had to completely respec everything. Even so, people were complaining before that.
Those people are wrong.
Changing passives needs to hurt (a little)
On one extreme, you could allow changes for free whenever the player wants. This has lots of bad side effects for the game. People will change skills on the fly depending on what content they are doing. There is no need to consider/plan anything in advance. Your character becomes just an experience platform. You grind the experience once and then you can change your skills/passives to be whatever you need. Skill gems basically already work this way, so passives locking you in at least a little is important.
"Don't tell me how to play my game!"
- It's not your game.
- The people who made it are concerned about the long-term health of the game.
Many streaming services have gone back to releasing 1 episode per week. Why? People binge content and then move on to the next thing. The entire time they complain about a lack of content. Building alts and trying different skills is a huge carrot that most players are willing to hang around for.
Just how bad is it?
I'm level 51 and each point refunded costs ~1,500 gold. I just switched from an aftershock titan build to a fire focus. It cost me about 15k gold out of the 90k I have. Mainly because all I had to do was tweak my passive tree around the edges. Here's my current tree.
Why was this so cheap? Because I realized what I was locking myself into was really this line:
Along this line, you can specialize. For example, in the image below, above the line is one-handed damage/effects and below is 2-handed:
So for me, I merely needed to drop some nodes and add some, but they were all close. I've highlighted some examples:
Gold isn't so hard to come buy
At my level, blue's sell for 200-500 gold consistently. Rares tend to be between 500-1500. If you need major surgery on your tree, it's doable. However, if you are going to wildly change that main branch, it's probably time for a new character.
Also, the cost of respeccing is cheaper when you are lower level. This allows you to play with those early nodes as you're building your character, but the more you develop along your chosen branch, the harder to change.
This seems perfect to me.
Conclusion
I'm not trying to write a treatise, so I'll end it here. This has all the hallmarks of a well-designed system. It encourages some degree of planning while removing the fear of bricking your character. I have been able to explore without the need for youtube vids, streamers, or guides. At 51, though, if I now want a totem-focused build or some kind of hybrid class that moves into dexterity or intelligence, then it's time for a new character.