Complex sentence: Besides being producers in their own right, the Etruscans were the main export market for Greek pottery outside Greece, and some Greek painters probably moved to Etruria, where richly decorated vases were a standard element of grave inventories.
Split into simpler sentences: Besides being producers in their own right, the Etruscans were the main export market for Greek pottery outside Greece. In Etruria, richly decorated vases were a standard element of grave inventories.