When is the price due in non-carrier cases?

How may a buyer revoke acceptance of goods? What are a buyer's rights to reject goods in an installment contract? What does the "ability to cure" mean? What factors limit a buyer's ability to reject goods? What happens if a seller wishes to cure beyond the time obligated for performance? What happens if a seller wishes to cure within the time obligated for performance? What is the buyer's right of inspection? What is the effect of a buyer accepting goods on his ability to reject them? What is the perfect tender rule, and what is the consequence of less than perfect tender? When is the price due in carrier cases, shipment contracts, and destination contracts? When may the seller demand payment in an installment contract?