What are the costs risks of bringing discrimination claims?

Any legal action carries costs risks.  Not tackling discrimination carries the certainty of further discrimination, which can result in destitution and sometimes even death. Judges have wide discretion over whether to award costs.

Whether the risk is worth taking depends on your individual circumstances.  The worse that can happen is you lose and get a bill for the other sides legal costs.  You would have to pay that if you can afford to.