Other than the fact that $7k still isn't that cheap (for many people)--how long does the "average" home of 4 take to recoup that cost? I think the barrier is n

Other than the fact that $7k still isn't that cheap (for many people)--how long does the "average" home of 4 take to recoup that cost? I think the barrier is not only cost, but also know-how. Few people are likely to tackle a challenging project like this with a $7k out-lay.