A couple of years ago at Christmas my husband bought me a yarn swift and ball winder. Or rather he let me do my own shopping since he's clueless about knitting treasures!
Always look for sales. Yarn swifts are pricey but you can catch good sales on them if you exercise some patience and vigilance! Which I did....like a cat at a mousehole! But when I finally pounced I got a great deal, saved about $30+. For the ball winder, I had a coupon for AC Moore for 40% of any one item at retail price. The winder they had is a nice one that works well and it was about $40, so I saved $16 and got it for $24. Also, I was shopping in Delaware and there's no sales tax there.
Although I don't use them that often, they are both items that come in VERY handy when you do need them. They're invaluable for winding yarn from "hanks", and I often use my ball winder when I get stuck with tangles in the middle of a center pull skein. Grrrrrrrrrr! one of my pet peeves!
(The swift is that umbrella looking thingy that attaches to your table that you can adjust to fit various sizes of yarn that comes wound in hanks rather than balls. Looking at a picture of it will give you a better idea than my lame description!)
Good luck with your decisions on these things. Let us know how it goes!