Depends on the building. We bought a house from the 40's on the small side (1500sf) that needed plumbing, electric service, all flooring surfaces replaced, kitchen guttend/replaced, both baths guttened/replaced, all appliances, and significant mechanical (furnace, water softener+filter), addition of closets, replaced deck, and probably stuff that I'm forgetting. Had a good roof, which was critical, because water damage would have sunk it (har har har). We did a lot of the work ourselves, saves a bundle. Contracted for about $40k of it up front to get it livable quickly.

Somewhat related to the story - I bought a pellet boiler off craigslist for $2800 and did 100% of the installation myself (electrical, plumbing [heat + water heater], control) all-in was about $3900, and I'm already in the black on it after 3 years use (vs. propane). I decided to burn lpg this year because it was 'only' $1.70/gal, and it turns out that even at that low price (compared to the last three years) I'd probably have been better off on pellets, but probably not better off enough to make up for all of the labor that it takes.

I set it up to automatically switch between the propane furnace and the boiler (I have a water/air hx) based on the boiler's temperature to make it seamless for my wife to use :). It's a Central Boiler Maxim M175 ... cranked all the way up, it might be able to heat his school (just barely) -- I run it at its lowest setting. Burns very clean, no smoke, happy neighbors.

Renovation can be done for a reasonable financial cost with an investment of time. Our house isn't super-luxury now, but it's perfectly serviceable and now we have a house on 11 acres that we couldn't have touched if it hadn't been a dump when we bought it.