Just ripped up old carpet and hardboard (2 bedrooms & landing) to find old pine boards underneath. The floors dip/sag in the middle due to age of property I think. Sanders came in and said they are ok (not great) but will come up reddish/honey colour. Electrician in today doing work under some of the boards said they're not in a good state for restoration. For the price, is it worth getting new floorboards - solid or engineered?