If I understood correctly, this sentence translates "He was buying food for seventy animals." or "He used to buy food for seventy animals." because of the imperfective form of the verb, right?
The other way around. He bought it. Once and done.
If we talked about repetitive action it would be KUPOVAL....
KOUPIT is the perfective version
KUPOVAT is the imperfective one
Oh I mixed up kupit and vykupit, which is already something else. Thank you!
Why not "koupil pro sedmdesát zvířat žrádlo"? Can't you stress the žrádlo here?
Yes, it is possible.