Not counting the time it takes to learn the craft, it can take at least 4 days to hand knit a sweater, and that's if you're really good and you're going constantly. If there are cables and color-work, it will take longer. Some knitters I know can bust out a sweater in a week, but that's only because they are fiendishly fast and don't really have much else going on in their lives. If there's school, or kids, or even a part time job? Psh. A month. A least.
But let's say our girl is really good, knitting at breakneck speed, and knits up a sweater start to finish in 3 days. We'll pretend she's paying herself the US federal minimum wage of $7.25/hr, and knitting 8 hours a day. That's $174 for labor alone.
Now let's talk materials. The average adult sweater takes anywhere between 1000 to 2200 yards of yarn. I haven't seen the sweater in question, but let's say she's using sport weight yarn and is knitting an adult small, so around 1400 yards.
My local yarn store sells locally sourced hand spun hand dyed yarn for $40 a skein/400 yards to a skein. So our girl is going to buy 4 skeins, so that's $160 for yarn alone.
We're currently sitting at $334 for a hand knit sweater using quality yarn.
This isn't including the time it takes to learn the craft, and the hours it takes design and work out the pattern.
But I get it. $300 is a lot to charge for a sweater, right? You can go to W*lmart or H&M and get a sweater for $20.
Big stores can charge what they do because they use machines, sub-par materials, and what's essentially slave labor.
I can only speak from an American perspective, but our culture and economy has destroyed the value of labor and has put convenience above quality.
Artisans are struggling. Fast fashion has given the general public the false impression that dedicated artisans are over charging when really? They can't make a living doing their craft alone.
$300 for a hand knit sweater is a goddamn steal.