The trouble is most animals are not raised outdoors. You need to find a good source to get a decent price on grass fed beef/lamb.

Agreed. My opinion is that we need to eat less, higher quality meat. Don't get fried chicken for a snack, cook a pasture raised chicken roast and use the leftovers. Better for us and improves animal welfare.

This still might not provide adequate vitamin D. But I think the demonization of fat is part of the Vitamin D problem.

Fatty fish like salmon or canned sardines are a relatively expensive but easy to obtain source.

Sardines are relatively high in arsenic so best to limit your intake.