I recently tested out a couple of more moderately priced rifles as compared to FX's, Daystates, etc. I will have to say that I was pleasantly surprised by all you get with the Benjamin Cayden (although what I tested was the .22 cal).
I was interested in the Marauder, but after having used side lever cocking actions I find it difficult to purchase any bolt action gun any more. And the side cocking of the Cayden is very nice and smooth - just what I wanted.
Its barrel is likely Turkish made (Kral?), but in my short time with the gun it has been MOA accurate out to the 61 yards I have shot it. And it would likely become better the more I shot it, and got used to it.
You mention wanting to fit a muzzle brake - which is not necessary on a .25 cal airgun as there is really no muzzle flip to control. If you meant to say moderator or silencer, then yes the Cayden can use any mod with the standard 1/2" UNF threading without needing any modification or accessories. And yes, my .22 cal benefited greatly from the addition of the smallest DonnyFL moderator, which would be even more necessary on a louder .25 cal gun to make it backyard friendly/more hunting ready.
I wonder whether Crosman stopped using Green Mountain barrels when they instead gave buyers the option of choosing factory fitted Lothar Walther barrels on the Marauder?
As your first PCP rifle I would definitely be more confident in a Benjamin product with its 5 year warranty and U.S. service center. Although I have never had the opportunity to utilize this warranty with any Crosman/Benjamin product I have owned - which is a very good thing!
The other reasonably priced rifle I tested against the Cayden was the Air Venturi Avenger. I also tested a .22 cal, but it is available in .25 cal as well. It was perhaps not a fair comparison as I chose to get my Avenger with the plastic stock, so it didn't feel as nice in the hands as the Cayden. But the Avenger is regulated (and the regulator is externally adjustable), and while I didn't like its trigger as well, it is somewhat adjustable (where the Cayden's is not).
In order to fit a moderator onto the Avenger you would need to purchase an adapter from DonnyFL. But perhaps like the Marauder, I found the Avenger's shroud to be effective in keeping the (.22 cal) noise down to backyard friendly levels on its own. YMMV with a louder .25 cal.
The funny thing is that while I didn't enjoy shooting the Avenger as much as the Cayden (due to its overall feel in my hands, and the way the trigger came from the factory), I could actually get more accurate groups with it on my backyard 61 yard range - approaching 1/2 MOA. And with a little more planted feel of the gun if I had chosen a wood stocked version, I may have liked it even more.
So these are just a few thoughts about other possible guns for you to look at which are in the Marauder price range. Sorry I can't directly compare them to a Marauder - the only time I ever tried to purchase one the vendor ended up having issues, I never got my gun, and I had to go through all of the PayPal hoops for months to get my money refunded.