I tried different brands of general-purpose acrylic paint pens -- for painting war game miniatures. I discovered that no matter the price, no matter the maker's brand, they are all pretty much the same for quality.
Their price tags are very reasonable, IMO, as well. Since trying the various branded paint pens, I now look for the lowest cost per pen/color, and I shop solely based on price. I prefer dual-tipped pens, as the brush tip is an absolute requirement, but the small marker-like tip also has its uses.
I also learned that in spite of only ordering "brush tipped pens", some ads lie and I wound up with hard tips which require that I press the tip into the pen body to get paint to flow over the hard tip -- these can scrape off primer!
I found a set of 12+ skin colored pens: various shades of brown and tan, and these are superbly useful! These shades of brown and tan are perfect not only for various shades of skin colors, but also for various shades of leather straps and bags!
I love these acrylic paint pens (brush tip versions!) as they are incredibly useful. However, they are not perfect.
The brush tips, and the hard tip models, have great difficulty getting into recesses. Having said that, though, they still speed up my painting, dramatically. I still use craft paint bottles and brushes to get to the recessed areas the pen tips cannot reach.
The pens are my go-to tool: no prep-time beyond shaking the pens, then removing their caps; when finished, I replace the cap, and grab the next colored pen I need. Zero clean-up time, no palette to mess with, no need for a wet palette.
Bear in mind that I am a simple block painting/assembly line style figure painter. They are superb, for me. I will always use these for the duration of my figure painting hobbies. They also work superbly for terrain painting. I LOVE their ease of use!
I hope this helps. I shop for them solely on Amazon. I have a Prime account, so S/H is usually free for me, which helps a great deal, especially when the majority of my orders are small, and shipping costs would likely equal or exceed the product's costs! My situation may not be typical, but it works for me. ;-) Cheers!