All I have left are the sleeves of a sweater jacket and my knitting store has run out of the yarn. When I started it I was told there was “plenty.” I am using King Cole luxury mohair in a varigated color. The owner of the store tells me the dye lot will not matter (she has ordered more) because it is multicolored. I don’t want to be paranoid but I don’t trust her. I can buy the right dye lot on the internet but I need her to help me with the rest of the pattern. I need opinions on the dye lot issue. Thanks so much - looking forward to some advice.
Since it is just the sleeves, I don’t think it would be that much of an issue. Even if you can still get the same dye lot, there still might be variation compared to the same one you already have based on how the yarn was stored, etc. If you had run out say on a front and started with a new dye lot halfway up, it might be obvious, but with the sleeves I wouldn’t be that concerned. Or at least until I saw the new dye lot yarn. 
It really depends on the yarn. I’ve had different dye lots of some yarns that look exactly the same; I’ve had some that look like an entirely different color. I think I’d take the chance on a multicolored, yarn, though.
Do you have the option of not accepting the yarn from your shop if it doesn’t meet with your satisfaction?
You can always come here for help if she won’t help you. If the yarn doesn’t match, you should have the option of getting the same dye lot and still ask her for help. After all, she could lose a customer that way, AND she did say there was plenty.