What is the cheapest way to send a Computer through the post (ebay)

[Jay1701]

I've just sold a computer on ebay. I've charged the guy £17 for insured delivery (about £50 cover should do)

Whats the cheapest way going about doing this as I need to buy the box and packaging.

and how am I going to know if the guy gets it. do standard parcels have a recorded service or something?

Ruled out collect + as they only take 50x30x30cm which is stupid.
its a mATX case

Options please guys! I wouldn't mind deviously squeezing a few more quid out of the sale as the auction did not go well (for me)

Thank you!! Much appreciated.
Jay

 

[Jay1701]

how much does an average computer weigh?

 

[Jay1701]

Well I'll be putting it in a printer box with a block of polystyrene top and bottom and bubble wrap and some crap like that.