John prices very so much by location its had to say what is a fair price, but the way i look at it is rust repair and paint/minor body work should be two different numbers...the car in question looks rusty to me, i would start with bead blasting the car to metal to see the real extent of rust...then the needed metal repair/replace will be shown (i have spent 150 man hours on rust repair)...here in texas two stage paint/body would be 10/15k single stage 15/20k...the rust looks like at least 5/10k...plus the cost to glass bead blast around 2k here...
to me its a low 20k plus project, would want to see other work/projects in progress and completed by paint/body vendor...