Sorry, I made a mistake when doing my comparison last night, here are the correct #’s:
FHA:
20% decline over 8 years:
$158,101.62 (8 years of interest) – $0(equity) + 14k (down payment) = $172101.62 (total cost of living in it for 8 years)

flat over 8 years:
$158,101.62 (8 years of interest) – $60723.87(equity) – 14k (down payment) = $83377.75 (total cost of living in it for 8 years)

20% increase over 8 years:
$158,101.62 (8 years of interest) – $140723.87(equity) – 14k (down payment) = $3377.75 (total cost of living in it for 8 years)

Conventional:
20% decline over 8 years:
$113,342.30 (8 years of interest) – $46907.76(equity) + 80k (down payment) = $146434.54 (total cost of living in it for 8 years)

flat over 8 years:
$113,342.30 (8 years of interest) – $126907.76(equity) – 80k (down payment) = -$93565.46 (total cost of living in it for 8 years)

20% increase over 8 years:
$113,342.30 (8 years of interest) – $206907.76(equity) – 80k (down payment) = -$173565.46 (total cost of living in it for 8 years)

As you can see, it’s cheaper to put down 20% even if you expect to lose 20% over 8 years. If your time frame is shorter, 3-5 years, FHA might be cheaper, but if your time frame is longer, ~11 years, conventional is definitely the way to go.