3 year old ipad not working

Apple offer a standard one-year limited warranty. Presumably you purchased your iPad within the UK while it was still an EU member state. As such, the iPad will have benefited from a mandatory two-year warranty.

However, under UK legislation, if you can prove that a manufacturing defect to be present when purchased, you have up to six years to make a claim. You should note that the onus is upon you to prove the defect existed when purchased.

At three years or more, you are well beyond your statutory warranty. Beyond warranty, you have benefit of access to paid repair services - and by your description, you have been offered this option.

Many iPads will continue to work without issue throughout their supported lifetime. As with any electronic device, you may be unlucky and experience a fault, or failure, sooner rather than later.

Trade-in isn’t available for any Apple device unless it is demonstrated to be working and without technical fault - the cost of repair typically being more than the potential trade-in value for qualifying devices.

For iPad, in lieu of repairing and returning your own iPad, Apple will generally offer an exchange for a renewed/reconditioned iPad of the same model and specification - at no additional cost. The exchange is much quicker than a repair - and if completed in-store, assuming that a replacement is available, is usually same day.