New boiler cost - reasonable?

[loopnoot]

We've been quoted £7,000 by British Gas for a combi boiler with a Hive thermostat, removal of the old boiler, immersion tank and water tank in the loft, and then 6 new radiators.

Is this reasonable? It seems a lot of money, and they said we can do a 4 year finance plan with 0% interest, but it seems an awful lot.

I've never done anything like this before though so I don't know what the usual costs are.

Any insight would be appreciated, thank you!

Got a glow worm installed by a local company (South East) last year and it was just under 3K. That cost included flushing the heating system, checking all the radiators and also fixing a leaky toilet cistern and installing a new toilet flush.