£1000 does sound expensive but it all depends on what the risks are and what the products being assembled are. Generally speaking you could keep your home insurance where it is and take out a separate liability policy for your business and this may be cheaper.
When it comes to insurance however it depends on the facts and what you are doing, even though I am biased working for an insurance broker, I would always give them a call and get some advice from them as opposed to going direct.
I get to see lots of small businesses who either pay way too much for their insurance or even worse aren’t covered properly as they don’t know what they should tell their insurer and then if they have a claim they either don’t get enough money or nothing at all.