When a headline is published claiming that broadband prices in the US are set to double in the coming years, our first assumption is that the findings have come from a report commissioned by a cable company. But this one wasn’t. The bullish forecast is from New Street Research, a US investment analyst firm with a reputation for being close to the mark. Comcast, the largest cable company in the US, will lead the charge in hiking residential and business broadband prices, according to New Street, which argues that broadband today is underpriced, having failed to keep pace with the explosion in penetration and usage. “Our analysis suggested a ‘utility-adjusted’ ARPU target of ~$90. Comcast recently increased standalone broadband to…