We have the 2008 escape. It came with remote entry, but we passed on the remote starter.
My wife would like to have the remote starter now so I'm shopping around. Bestbuy installs their systems free of charge, but it's an extra $140 to install one in a car built after 2007 because of the Federally mandated security systems. It was also going to cost an additional $40 to wire each window if I wanted a fancier system that can open the windows and turn on the rear defrost.
So I checked ebay, they have all sorts of systems. There's a bunch of after-market systems that claim to work by temporarily disarming the car's factory security system. These are a lot cheaper, and it doesn't look like it would be difficult to replace the fobs. Some you can use the door lock button on your fob or some other combination to start your car remotely. That would be best for me, because I wouldn't need to carry any additional fobs with me.
Just like to hear some feedback from people who have installed these systems and used them.
You don't have a factory alarm disarm wire, maybe on the databus and that's why they want the extra money. You do have a transponder key which there are a couple ways around but each cost money.
I would get a quality alarm and RS unit. You can have the system as integrated as you can afford or wire. Going this route, you would need the factoy the factory key fob at all, and some of they new systems offer 2 way remotes so you can be paged (if within range) when you alarm sounds. I love my Compustar pro system with 2 way remote, and tap sensor that lets me tap in a code on the rear window to unlock the doors and disarm the system. In effect I can lock my keys and fob in the truck and as long as I have something hard to tap on the glass with unlock my truck when I want.