I'd actually suggest staying away from the knitting idea, unless you know someone who will do it for you for free and is an experienced knitter. You'll be in at least $300 and probably more like $500 for the yarn alone. It takes a lot of yarn to knit a sweater, even more to knit a cowl neck sweater, and cashmere yarn is expensive. And if it doesn't fit, ugh! (I'm a chronic returner too, so I know exactly what you mean.)
Before I started knitting, I always thought it would be less expensive to have something knit for me. My first sweater was with very affordable wool yarn, cost me around $200, took a ton of my time, and fits, well, so so, even with my very very experienced master knitter friend helping me make tweaks to it. My sweater was a cropped one with a big cowl neck--a style I adore. I've barely worn it. Lesson learned for me.
FWIW, Souchi is amazing stuff. I have this in light blue cashmere. I bought it as a special treat after my son was born. The cashmere is incredible. Very nice weight--heavy yarn, but light in weight. The sweater is still gorgeous after 5 years. It was ultimately one of the best values I've found. And I have a cropped little puff sleeve sweater that I bought before that one. Still in phenomenal shape. I don't like the style as much now as when I bought it, but it makes an incredibly luxurious short robe to wear over pjs.
You might consider stalking the cowl neck until the end of the season to see if it will go on sale for a price you can justify. The shape is classic and beautiful. If you get it in a color that you love and you keep it forever, it can be worthwhile. BTW, I also hand wash mine, so no dry cleaning bills. That's the joy of very nice cashmere.