Something is very wrong in some countries if you have to get police protection to sell a f* computer. I get it’s on the expensive side but still….
Police "safe trade zones" are basically a parking space outside a police station, with a sign.
The buyer doesn't know who the seller is, and vice-versa... the level of trust you can bear depends on how much you're willing to lose. My advice is only in that there are safe venues you can use to make such an exchange.
If it is an electronic payment, I'm not sure how completing the transaction in front of a police station will help any. Well, it will help the buyer to see it working, but the seller gets no additional protection besides seeing "a person."
That's not the point of going to the "police safe exchange zone".
The point is to hopefully prevent the possibility of the buyer showing up with a .38 in hand, and demanding to be given the easy to fence "item" unless the seller wants to get a .38 slug embedded in their gut.
The risk of a "hold up" increases with dollar value and with items that are easier to fence.