Last year I bought a house (for use as a rental) that had significant foundation, dry rot, plumbing, and HVAC problems. The house was in a fantastic location and priced below market value.
My inspections came back with about $40,000 worth of work needed. My real estate agent and I negotiated the price down $30,000. I had all the work done myself (NOT by the owner.)
The result? I now own a house worth around $480,000 that, with repairs included, cost me $365,000. And I rent it out below market rate too, so everyone wins (I hope
Because I was paying cash and this is was an (empty) rental, I was not personally put out (having to live with contractors, no water/heat, etc. Or dealing with 2 mortgages.)
Where I live, barring some major disaster, property values are unlikely to ever decrease. In the downtown historical district I purchased, prices are increasing 12% per year.
So, it's complicated.