Hi,
As written in the product pages :
No limit of time
1 year free updates
1 year free HikaShop support for one website
There is no limit of time which mean that HikaShop will continue to work even if your license as expired.
But, if you update an HikaShop Business using an HikaShop Starter package, you will loose the Business features.
You won't loose your data and you won't loose your custom field, but the feature will be deactivated.
Otherwise, please note that the price of the renewal is cheaper than the product price, specially if you renew for two years.
Regards,