I worked up the plans in my head for about a year before my mother finally got around to having me build her 10 foot farmhouse table. That's right, this bad boy is TEN FEET LONG! And it was one of the simplest things to construct!. I used 8 foot 1x8's for the length of the table (used 4, making the table 29" wide) and 1x12's for the breadboard ends. We also splurged and purchased turned legs for $15 a piece at Blue. It really made the table extra special. Totally cost, with finishing supplies came in under $150.
Things I would change if/when I do a table of this size again:
1) I would never make a BB end so large again. I would stick to a 1x6 or smaller. With such a large size we worry about children putting too much pressure on the ends.
2) I will make the legs removable. It was a bear trying to get this table into the house. Thankfully the width was just narrow enough!
3) I won't tackle this in the winter months! Construction of the table took only a few hours but finishing in freezing temps took weeks waiting for warm-ish temperatures.