Ah... comparing home costs per square foot. I built a home a couple years ago (as an investment) and took great pride in tracking the costs of every brick, nail, and 2" paintbrush. In the end, I was quite satisfied with my $/sf and made a fair profit on the sale. When friends asked about the numbers I'd recite them all and, unimpressed, they'd respond, "Oh really? My cousin's friend builds houses and she says that he turns a 30% profit on each one." Then they change the subject.
I used to fret about it, wondering, "Does her cousin's friend count transportation costs for trips to the build site? How 'bout property taxes paid during construction? Realtor's commission? Title fees?..." I was always dissappointed that people weren't more impressed with my numbers. But I've learned to live with it.
The fact is, those people don't know what it really takes to build a home - not like you and I do. If you built a custom home you are happy with for a reasonable price (and it sounds like you have) then take pride in that.
And if someone asks about the numbers... LIE

Take the simplest total of materials and direct labor, divide it by the most generous possible estimate of square footage (don't forget cellars, carports, and tree houses), round down a few dollars and proudly say, "I spent about $70 a square foot!" If anyone doubts you, tell them how you found some great bargains on cabinets, tile, etc... who knows... maybe they'll ask you to be GC for their next home!