What is the cheapest courier you think I should use, that are available in the UK, for sending computers and laptops?
So far I have looked Royal Mails ParcelForce, DHL (expensive apparently), UPS.

Can someone have a go at this please, thanks.

Are you in the UK or sending to the UK from overseas? Speed of delivery will also impact on price. You should be able to get prices from the respective company websites without problem.

I am sending from the UK to the UK mostly but may expand later on...

I had a look at many companies last night including parcelforce, postvan, UPS etc...
Has anyone has any experience with postvan before they seem to be fairly small?