For much less than that, you can get a Viper 4816 installed. I had the Viper 4816 installed in my Outback last year. Including installation, it was $420. And the Viper has some real advantages over the Subaru OEM remote start.
First is range. The 4816 comes with one 2-way remote with a mile range and one 1-way remote with a 2000' range. While I honestly haven't gotten that sort of range out of them in real world conditions, they still get much more range than the 300' that the OEM remote start is claimed to have.
Second is that with the Viper, the engine doesn't kill when the door is unlocked. With the Subaru, it does. You then have to put the key in the ignition and restart the car.
That is part of Subaru's theft protection system.
The Viper uses a different theft protection system requires the key to be put in the ignition and turned to the run position before the brake is pressed. This keeps the car from being put in gear without having the key in the ignition. And it is effective. Trust me. I typically "verify" (yea, that's what we'll call it) that they system is working correctly about every two weeks.
Lastly, the Viper has a lifetime warranty when installed by a Viper authorized installer.
I had a mile range viper installed on my new 2009 Scion XB. I LOVE that thing. I can be standing in the grocery checkout line, hit my starter and it will crank my car from the back of the parking lot. In the winter time, that is a serious luxury.
The little remote I had, showed a picture of the car. If it starts, you get a visual confirmation of exhaust coming out the back of the car on the remote. If it didn't catch, you get 3 beeps. If someone messed with the car, the little remote even tells you which window was tapped on.
I now have a 2017 Outback. I'll be getting another Viper starter. When I call around, it's about $600 for the top of the line Viper installed.