If I play a card mistakenly (not enough resources to complete), but a neighbor in the same turn built a structure that produces this resource, can this resource be bought to complete the construction?
If I play a card mistakenly (not enough resources to complete), but a neighbor in the same turn built a structure that produces this resource, can this resource be bought to complete the construction?
No
Same rule as with coins, you can't spend coins that you don't "own" yet.