Are you a tinkerer? Strictly a shooter? A little of both?
I'm a tinkerer, so the Marauder is right up my alley.
My 2 Marauders are both fantastically accurate,reliable, very quiet, easy to work on with endless possibilities to build it the way you want it. Could do a complete tear-down and rebuild in about an hour. Albeit a bit on the heavy(er) side, there are many nice guns in the 8-10# range scoped. If you buy a Marauder at a fair price compared to an FX, there is potentially money left over to round out your system while tinkering.
Both of mine are .22. One is synthetic and the other is a F&T w/ LW barrel and regulated. Shooting either under 60 yards is not a challenge. 75-100+ is where it's fun.
I have an FX Dreamline Classic synthetic as well, in .25. I bought it used. I love it.
When I got the FX and shot it for the fist time I realize that what I was trying to build the Marauder into was... what FX had already done. My cost and time (not a problem) that I put into the Synrod with a Huma, Hill valve, LW hammer, PEEK, TP,... exceeded what I paid for my used Dreamline. Was lots of fun tuning and tweaking the Marauder and have learned a lot with the help of folks here as well as other forums.
Would I go for a Marauder today after having my FX? Not a chance. Will I have another FX? Yes.
I would also throw out a few other fantastic air rifles in the same "used" price range as an FX Dreamline. I have seen all of these advertised for under a $1000.
Daystate Huntsman, Daystate wolverine, AA S510, BSA R10, as well as those that others have mentioned.
Have fun in your search!