I spoke to a service, and I was intending to use them. The price hadn’t been finalised yet, as they needed to see the home in person, but they gave me an estimated price However, someone else then helped me, so I no longer needed the service. But is it fardh to use their (expensive) service still?

Ustadh AbdulAziz al-Haqqan

No, since the deal was not finalized and you didn't give them your word, the transaction actually didn't happen. Therefore, this is not binding.