Listing periods for Employment Tribunals vary, but it usually takes between three and six months, from the date that the claim is issued to the Tribunal hearing. At the moment, however, Tribunals are swamped with equal pay cases, so it may take considerably longer.
The cost depends on the nature and complexity of the case, and to some extent on the area in which it is being brought. A straightforward, one day, unfair dismissal hearing would probably cost between £3,000 and £5,000, assuming that a solicitor (based outside London and the south east) was acting for you throughout.
Discrimination cases are invariably longer and more complex - and therefore more expensive.