'IKEA Effect' (Loving the Crappy Furniture That You Assembled)

People who assembled IKEA furniture themselves will pay more for the assembled object than for the same, pre-assembled (80 cents instead of 50 cents). Why? People value their time spent and can’t escape the sunk-cost fallacy? Consistency? (“I wouldn’t have assembled it if it weren’t worth assembling” - though they were paid to participate).
When you perform unskilled labor, do you value your time at the price of unskilled labor? 

Does this hold for more valuable objects?