You will pick up a reasonable Theoben Rapid Mk1 for that Money, the Rapid was designed all those years ago as a Fac rifle, where as most of the others lister were Sub 12ft lbs, you need a reasonable sized pre chamber to get consistent results, but the Rapid Mk1 has no Regulator, this is not a problem if you know how to balance the springs, a well fettled Rapid is a match for any of the ones listed, even FX the smooth twist barrel on the FX models was a Ben Taylor ( of Theoben ) idea he sold to FX when Theoben were bought out and moved to the USA, I might be biased though because I have 4 of them and 2 in build , I'm going to use a FX heavy slug liner on one of them, should be pretty good out to 200 yards
FAC Rapids are cheaper to buy if you have a slot on your ticket, because it's a limited audience.
Good luck in whatever you decide on.