• Merchandise is purchased on open credit for $800,000. • $100,000 is returned to suppliers, the amount of which is credited to our account. • Suppliers grant rebates on account of the debt for $50,000. • Suppliers are paid $400,000. • Merchandise is purchased on credit for $950,000, for which a 30-day promissory note is signed. • The previous purchase is returned to its suppliers for $70,000. • Suppliers grant discounts on the last purchase of $80,000, which they credit to the account. • Suppliers are paid $500,000.

We can keep track of the net amount owed to suppliers by adding and subtracting all transactions:

1. Initial purchase on open credit: $800,000
2. Return to suppliers: -$100,000
3. Rebates granted: -$50,000
4. Payment to suppliers: -$400,000
5. Second purchase on credit: +$950,000
6. Return of the previous purchase: -$70,000
7. Discounts granted: -$80,000
8. Payment to suppliers: -$500,000

Calculating the net amount owed:
$800,000 - $100,000 - $50,000 - $400,000 + $950,000 - $70,000 - $80,000 - $500,000 = \boxed{\$1,050,000}$

So, the total amount owed to suppliers after all transactions is $1,050,000.