1) Does it require re-application of gel coat? Can't say based on a picture. It depends on the depth of the damage and the thickness of the gel on that part of the boat.
2) Given that it's a 2006, and assuming the boat was primarily trailered, then most likely it's due for a refinishing. If it was only trailered once a year you probably can buff it out (or just leave it be...)
Ugly gelcoat is easy, well blended gelcoat is difficult. Adding to the challenge is how do you repair the area where the boat rests on the bunks while the boat is on the trailer??? This makes what could be a simple repair a little more complicated. A fiberglass shop would use a forklift to lift the boat and then support the hull appropriately with a craddle or adjustable posts. This step in itself requires some experience to avoid the posts moving and the boat ending up on the ground causing further damage.
If it were me, I'd pay the $1000-$2000 repair if a repair is required (if you have deep gouges exposing fiberglass).... if it's just surface surface marks and material transfer from the bunks I'd leave 'em be. Looking closely at the picture, I'd say you have some exposed fiberglass and are in need of a repair (can't tell for sure with a picture, would need a physical inspection). The re-application of gelcoat in itself is quick and does not require a lot of materials. What you are paying a pro for is the setup, prep and finish.
1) setup: place the boat securely on an appropriate work stand
2) prep: mask the entire boat & prep the repair area so that the new gelcoat forms a permanent bond
3) finish: by sanding between coats and going through a 2-3 stage buffing/polishing process afterwards, you can get an almost seamless blend of the new and old gelcoat. You can save a few bucks if you tell them you don't care about colour match. However, if you allow them to correct the oxidation on the hull and they match the colour, the repair can be virtually seamless from 5 feet away. You could also ask them to build up the thickness in that area if you are planning on keeping the boat.
Gelcoat can be applied with a brush or with a spray gun. Sometimes a combination of both is used (brush for deep repairs, spray gun for final blending). Results are dependant upon correct mix of catalist for the temp/humidity.
What's the condition of the rest of the boat? Is it worth investing $1000 to $2000 into it? If you just want to patch exposed fiberglass quickly and easily, MarineTex and some wet/dry sandpaper will do that without much hassle.