Some retailers keep a small loyalty or retention discount available, but it's only offered when a customer actually asks, usually through live chat or by mentioning they're considering a competitor. These aren't published anywhere on the site.
The pattern that tends to work: reach out through live chat (not email, which is slower and less likely to have a live agent empowered to offer a discount), mention you're a repeat customer, and ask directly if there's any current loyalty offer available on your account.
This works best for subscription-based services and mid-size retailers with a retention team, since they'd rather offer 10-15% off than lose a recurring customer entirely. Very large marketplaces with fixed pricing structures are less likely to have this flexibility built in.
It's worth noting this isn't guaranteed every time, agents don't always have discretion to offer something, and asking politely once is enough, repeatedly pushing after a clear 'no' won't change the answer.
The technique costs nothing but a two-minute chat message, and works often enough that it's worth trying before assuming the listed price is final, especially for any service you're renewing or already use regularly.