Just did ours 3 months ago, knocked down wall between dining room and kitchen so we got an open plan. Got different qoutes such as 5K, 4.5K, 4K. We got a contractor who did for us for 2800 (including electrician). They were very efficient and finished the whole job in 3 days. Very satisfied. If you live in South East I could give you his no. Send me a private message.
Most of the contractors would know if it's a weight bearing wall. But we confirmed it with the builders of our estate to check the blueprints. We didn't need a steel. Steel would only cost additional EUR200 according to the contractor who did the job.
Goodluck.