Is a cheap device automatically a bad one?
Answer first
Not automatically. Instead of price, check the update-support end date, unique credentials and a security reporting channel.
Security does not require the newest or most expensive model. A device that is already out of support is a poor choice regardless of price.
Price may reflect materials and features, but it does not show the support period or how the manufacturer handles security reports.
Look on the support site for the model’s support end date and a public address for reporting a security problem.
If those details are missing, the purchase depends on guesswork.