Oh, the uncertainty!

I'm plugging away at my blue sweater, actually very pleased with how the short row sleeve cap turned out. But, I'm not at all sure I have enough yarn to complete both sleeves. I was sure before I started knitting the sleeve, but now, holy cow this thing is consuming yarn! Possible solutions: turn this thing into a vest or buy some additional contrasting yarn to knit sleeves with (bonus, since it would be a solid colorway, I could just knit the sleeves in stockinette, much faster). I'd probably have enough yarn if I just made the sleeves stockinette, but the very reason I chose this stitch pattern is that I don't at all like how this yarn looks in stockinette. So there. Next choice; continue knitting on to find out if there is enough yarn, or cut my potential losses and head straight to plan B (or C)?