If all you want is remote entry (RKE) without a panic button or remote start, then an aftermarket product may be cheaper to buy and install.
And the nice thing about it is you can get the RKE kit, install it, then tap into the car's existing wiring to the lock actuators.
If you want the remote start feature then you'll have decide whether to get the factory fobs (if it's even available on your model), or get the aftermarket product along with a bypass module for the key. More money than RKE, but the one I had on 2 previous cars had a 2-way remote that reached 2 city blocks! (No kidding.) Another nice thing about 2-way remotes is you get a sound and/or visual signal that the command you just sent was accepted or not - no guessing! Those two features I really miss.
Check all your options before deciding, then pull the trigger.