I’d say that you need around £800 to £1000 for a basic HF station. Unless you’re particularly interested in construction and have the technical skills to repair/restore older equipment, a new rig , a good ATU and a DC power supply is a must for new operators. I have known new licensees who have bought secondhand and got very dissappointed and some have even given up altogether on the basis of bad experience. If you want to operate, buy new or reputable secondhand only. Entry level rigs can be bought for around £500 to £700: these will be portable types that will give good performance and work quite well, but wont have lots of dials and controls. An antenna tuning unit may cost around £175 for a manual model or £250 for an automatic type. Antenna prices vary enormously but I would suggest that making a simple wire dipole for your chosen band or perhaps a doublet. Commercial vertical antennas may cost around £300 upwards for HF. Beams and rotators – more still.
Computer logging is the norm these days, but not mandatory. It is convernient to have a laptop alongside the station transceiver for logging. This will also allow you to use data modes and operate contest CW.