I am looking for suggestions for a mid-layer upper. It needs to be light weight, warm, synthetic fill and not bulky. The north face thermoball jacket seems fits the bill but the price tag is a bit high ($200). I will be using this for a spring trip in Colorado. Any input would be appreciated!

I have backpacked for years in western NC but, this will be my first trip to CO. I know I need something warmer out there but I not sure a jacket like the thermoball will be enough. My other layers are a capelin shirt, another thicker synthetic shirt and a rain/wind jacket.
Thanks for the help