Over these years, Apple has introduced many new technologies and features on the higher-end model. And to keep the iPhone SE cost as low as possible, only essential upgrades are added to this new phone. It allows user to have a compact phone which is pack with powerful specs yet does not burn a hole in their pocket.
The good news is that some telcos are bundling iPhone SE free with their contact mobile plan. Otherwise, you may choose to sell your existing iPhone 7 or 7 Plus and use the money to cover the cost for your new set.
In terms of technologies, there are not many huge leaps between iPhone 7 and iPhone SE. However, the little improvements may give some users the push to ditch their current phone for an overdue upgrade.