In order to be concrete proof that you are selling the computer, can you embed a link to the computer image sold.
It takes a visual appearance for there to be proof that you sold your computer and also bought an amount of 0.006 BTC.

Want to sell whatever it is the decision of the owner of the goods and start investing in Bitcoin.
I've even sold my bike to invest in Bitcoin in the past.
Long-term holding will certainly be worth it, but 0.006 BTC is still very minimal enough, you need to do DCA if you have other funds later.