if you look how they are build. Evanix has a more massive receiver, but the design on the Marauder is better.
marauder has a Chinese made wood stock (and some parts) that needs to be redone so it feels like wood. Pressure gauge needs to be replaces because the spring inside it rattles when you fire the gun. Same as on Evanix AR6 models, you hear that strange noise from it.
But the barrel on the .25 Marauder is made by Green Mountain, so it will be accurate. Also the valve stem on the Marauder needs to be replaced it is very thin being hit by the heavy hammer. But these are small mods that won't cost you much. And barrel band on the marauder may need to be replaced, some of them have large gap around the barrel shroud.
Evanix Blizzard family have air escaping from the side of the mag, (causes excessive noise) nothing is sealing between the mag and the barrel so you get some air leakage when you fire the gun. Also on some models the mag holes don't line up exactly with the barrel as you cock the gun, and the mag rotates, that will damage skirts if you shoot JSB's, that is why some people say it only shoots Eunjins, that is not as easy fix problem if you get a gun like that.. And another thing evanix valve body to which air tube is attached has drill marks for set screws that that hold the hold it inside the receiver underneath.
So if you can spend a little ($150)more get Air Arms S500 or S510, these are one of the best all around made PCP's at any price. It is made better then a Daystate Air Ranger if you analyze how they made things on these guns. Everything is done with a thought, only missing is a regulator. HW100 and S410/510 are the pcp's you can't go wrong with, and that absolutely worth every penny.
Marauder and Evanix in my opinion are about the same value,- guns that need works, Evanix has a better wood and looks nicer, but the Marauder is designed better and simpler to work on.
But again for $769 you can get an Air Arms S500 Xtra FAhttp://www.pyramydair.com/s/m/Air_Arms_S500_Xtra_FAC_PCP_Air_Rifle/2392
which will be a good investment and it will be a super accurate rifle, because of LW premium barrels they use. It is a single shot though but you can shoot longer pellets with it something the 510 won't do.