I wouldn't count on the HM Revenue & Customs agents not being able to use the internet to find out what you probably paid for that laptop in about 30 seconds.
Won't you pay VAT and import duties as well? It might be more than 20% in total.
You need to check that to be sure what your total cost would be.
It might end up being cheaper for you to pay for an airline ticket for your friend to courier the laptop over to you.