What are the ids of suppliers which have an average amount purchased of above 50000 or below 30000?
SELECT supplier_id FROM Product_Suppliers GROUP BY supplier_id HAVING avg(total_amount_purchased)  >  50000 OR avg(total_amount_purchased)  <  30000
50000'ün üzerinde veya 30000'ün altında ortalama miktarda satın alınan tedarikçilerin kimlikleri nelerdir?