Roughly speaking, what should I expect a typical repair to cost on a damaged vehicle?

This varies too widely to estimate from a listing alone — it depends on the make and model, parts availability, labor rates in your area, and the true extent of damage once a mechanic actually looks at it. As a rule of thumb, experienced buyers get a quote from a trusted shop before bidding on anything with real damage, rather than estimating from photos, since hidden damage is common with salvage and damaged-title vehicles.