The gray part is a 43713 "Wedge 6 x 4 Triple Inverted Curved". It has appeared in 231 sets since it was introduced in 2003. Your picture looks like light gray. This part has only been in 28 sets in Light Gray or Light Bluish Gray.
I found it on bricklink by searching for "curved 6 x 4". I also tried "curved 4 x 6", "fuselage", and "bow" (as in the bow ...
These 2 sets 75243 & 75258 are 2 of the 20 years anniversary sets.
LEGO included in each of these sets an additional minifig on a stand based on the minifigs released during the first years. These initial star wars figures still had the yellow heads before they moved to flesh colored heads. So they have recreated / replicated these original minifigs.
This is from
75155-1: Rebel U-wing Fighter
Keypart : 6180pb115L : Tile, Modified 4 x 6 with Studs on Edges with 5 Worn Blue Rectangles and Black Lines on White Background Pattern Model Left Side (Sticker) - Set 75155
Based on the parts
Left Shell 3X10
Rocket Step 4X4X2
2M Fric. Snap W/Cross Hole
and the Technic rubber projectile launcher
it should be (as Uli commented) 7672-1: Rogue Shadow:
Product description (cannot embed URL for description, so you have to click on "DESCRIPTION" tab) explains why adults are a target audience. (emphasis is mine)
It’s a super LEGO Star Wars™ gift idea for adult fans and offers a
testing challenge for experienced LEGO builders, with the familiar
shape and authentic details of the helmet beautifully ...
If the sets are indeed complete with all parts, minifigs, instructions and even boxes then I'd recommend Bricklink, as the collector community there would be more appreciative of these features. Whereas on Ebay and Craigslist you'd find more people who just want a playset and couldn't even tell if a set was complete or not.
For higher value sets (like yours)...
First, movers are widely varying in quality. You might get folks that are poets and scholars or you might get somebody that drops every box. If you've gone with the cheapest movers or this is your first move, it is probably best to assume the worst. To me this means it is comparable to shipping something through the Post Office.
Given the size of this set ...