The reason I got a in-built GPS is because I sometimes forget to lock the RAV and I lost my GPS, coat, gloves, ....
I no longer need to unplug and hide the GPS and wires everytime I leave the RAV or find out I left the GPS home when I really need it.
But above all, i wanted Bluetooth capabilities for taking/making calls.
If I had BlueTooth in my RAV, I would simply gotten a portable GPS and lived with all the inconveniences mentioned above.
You have a few choices since GPS is what you are really looking for:
1. OEM Toyota unit - Expensive, pretty reliable, need to pay $100 for a map update, most early units did not have BlueTooth capability and you would also need to get an extenal mic routed
2. Chinese units - about $350 on ebay. Better than OEM look. Maps can be updated easily by "sharing" from the web. Not every stable. Many of them have quirks. Mine loses volume for weird reasons 4 or 5 times a year but it is value of money.
There are dozens of dealers on Ebay sellting these units. Try to buy from a USA dealer so that you can easily return for warranty/exchange.
I bought mine directly from China but the price is same nowadays on Ebay and you won't have to pay Duties.
The good thing about these units is that you won't have to spend another $50+ to just to get the steering wheel adpater and Scosche bezel for the unit.
You can read reviews of my "Henhao" unit on this forum; not the best unit but I am keeping it.
3. Get a good quality unit. It will cost $700+. But you will be able to move it from car to car as you upgrade (although many cars incl 2013 RAV4 come with radios which control car settings; so you won't be upgrading those anytime soon). They are much more stable and reliable. You get what you pay for. Good warranty. You will need to get the Scosche kit for the unit as well as the Metra wiring if you want to use steering wheel buttons. Common brands are Kenwood and JVC. e.g.
Kenwood DNX6990HD Install, just a few quick findings.
BTW, this Metra unit (known brand name) looks good. http://www.ebay.com/itm/TOYOTA-NAVIG...#ht_659wt_1238
Ok warranty. Buyer pays return shipping though but better than shipping back to China!
You could also look at Scion units (and may be other Toyota units) that would be plug and play. Of course, you would still need the kit and harness if you do not have the Steering Wheel buttons already.