Why do renewal prices vary so much?

Renewal prices can vary for several reasons, even for customers with similar packages. Here are some factors that might contribute to the differences:

1. Contract Terms: The terms and conditions of your original contract might differ slightly, leading to variations in renewal offers.
2. Promotional Offers: Your son might have been eligible for a promotional offer or discount that you were not.
3. Customer Loyalty: Companies sometimes offer better deals to customers they consider more loyal or at risk of leaving.
4. Negotiation: Sometimes, the outcome of a renewal offer can depend on how effectively a customer negotiates with the service provider.
5. Market Conditions: Changes in market conditions, such as increased competition or changes in the cost of providing services, can affect renewal prices.
6. Usage Patterns: Differences in usage patterns or service needs might also influence the renewal offers.

If you feel the renewal offer you received is unfair, it might be worth contacting Virgin Media's customer service again to discuss your concerns and see if they can offer a better deal. You can find more information about their pricing and renewal policies here. Our annual price change explained | Virgin Media Help

They give random prices in the hopes you won't bother questioning it. That's how they make the most money by fleecing loyal customers.

It is quite clear the price becomes what the customers will bare. 

Customer inertia is so high, allowing a low level of churn is working out
fine  for VM as often those former customers return 3 or 4 months later
on a new joiner deal.

Then the cycle starts again !

Putting your respective postcodes into the usual price comparison sites what does the like for like competition look like for each of you? I suspect VM has some sort of database tracking competition locally and will pitch renewal pricing accordingly.