"Paying for shipping is a huge mistake on Cyber Monday," Dengler says.
Many retailers offer free shipping during the holiday season, he points out.
Target, for example, is offering free, two-day shipping with no minimum through Dec. 22, and Best Buy is offering free standard shipping with no minimum purchase.
Amazon Prime also offers free, two-day shipping on eligible items to its members, so Cyber Monday is the perfect time to consider signing up for a 30-day free Prime trial. For everyone else, it's offering standard shipping with no minimum purchase amount for a limited time.
Plus, a Prime trial will also likely yield special deals exclusive to Prime members. "Last year, Amazon offered exclusive deals to Prime members only on Cyber Monday," Dengler says. "It is likely it does the same for 2018."