Based on sales over the past 2 months, a typical price per square foot would be around $200. Of course it varies by town and property type. Larger Colonials on 2-3 acres in the 1 million range could reach the low $300's per foot if the quality level is fairly high. Also, you get some high readings from older vintage Colonials on larger sites. An 1820's era Colonial on 12 acres in Tewksbury could sell for $500/ft. Overall though, most of the data seems to indicate $180-$240 for "typical" homes. If you need more detailed data for specific towns, contact me through my website.
Happy New Year!