As Bigsparks says, the difference in cost between non fire rate and fire rated down lights is minimal. In fact, I go further to say you'll be hard pushed to find a decent non fire rated DL. Even reasonable quality LED DL are manufactured to comply with Part B, but some also Part C & Part E.
Cheapest DL at Screwfix for example, non rated with lamp is about £4. Cheapest fire rated, with lamp is £7. But then your client might start moaning, when the cheap LED lamps start failing. There's decent DL now for sub £20.
Cheapest DL at Screwfix for example, non rated with lamp is about £4. Cheapest fire rated, with lamp is £7. But then your client might start moaning, when the cheap LED lamps start failing. There's decent DL now for sub £20.