Hi There!
JP and BW and two very reliable firms who have put a good bit of effort in producing quality saxes - 2 of the best under £1000, and much better than some of the "cheaper" stuff that is around. John Packer are a well established firm - I bought a Tenor Trombone from them (JP231/Rath) which, at £365 is easily one of the best under £1000. These are all made under licence in Taiwan, and a lot of effort has gone into training up a skilled workforce under supervision. Just make sure you invest in a decent mouthpiece (Rico Graftonite and Yamaha and two very good cheapies at around £30). I would personally go BW if pushed but would be happy with either.
Kind regards
Tom😎