I’ve knit a ton of baby bibs–I’d rank them way easier than afghans, purely because they are small and therefore finishable. (I have no interest in afghans.)
Fifty dollars is cheap for an afghan, I’d say. Five hundred is not impossible, but seems likely to create a masterpiece which then sits on display where no one can touch it. I’d aim for a hundred dollars as reasonable for the cost of an afghan.
Sock yarn usually costs me about twenty dollars for a pair of socks, but I don’t knit thick wool socks, and thick wool can be a lot cheaper than fancily dyed skinny wool blends.
Patterned vs. Solid may or may not affect the price. It depends on what the pattern is. One can buy yarn which is already multicolor for prices not all that different from solid color yarn. Or, if one needs 20 skeins of yarn for an afghan (number pulled from my hat), one can buy 10 blue, five red, three white and one yellow for more or less the same price as 20 blue.
But the patterned beanie might well require several times the number of skeins of yarn of a solid beanie. Because you may only need a little bit of some of the colors. So you might be able to make several beanies from the yarn.
And don’t forget the cost of the needles! My new big box 40% coupon needles were like 2 bucks, but they aren’t nearly as nice to knit with as my fancy new needles from a local yarn store (which cost eighteen dollars) (Addi Lace Turbos, for those for whom that means something).
Sweater? I’d probably budget one to two hundred dollars, but must admit I’ve not actually knit any sweaters larger than child size–and for the children, I used cheap acrylic. or cheap cotton. That’s a goal for next winter. After I knit up my sock yarn purchased for lace shawls.
Time commitment? Varies. Bibs I turn out in a few hours of very casual knitting.
Afghan? too much time commitment for my blood.
Sweater? likewise.
Adult size beanie? only adult sized hat I’ve knit I did so in a day or so. The more complicated the pattern, it might take longer. Also if you use skinnier yarn.
Thick wool socks should actually not take forever, compared to skinny socks, because you use bulkier yarn. I tend to knit intricate socks which take me a month or so a piece. But when I’ve used heavier yarn, I knit a sock up in a few days.
Of course, most of my time commitments are “elapsed time” rather than “knitting time”–it’s just easier for my to keep track of when I started and stopped rather than how long I spent knitting. It should be noted that I am not a monogamous knitter. So I’ve got four hedgehog mittens on my desk, a shawl at my feet, and somewhere not far away, a sock toe begging to be frogged (ripped out) and restarted.
Well, and plotting for lace shawls has shown me I don’t really want to think about how many stitches are involved in socks . . . 3915 down, only 15324 to go. Oh, and nupps. I’m ignoring the nupps. (Swallowtail, in case someone knowledgeable is wondering).