How long should one wait for payment?

Good that you have had some contact. A week is the general time unless something else has been organised. Give them a set day to receive payment by and stick to it. If that day comes and no payment, then apply to Trademe for a fee refund. They will give the buyer 3 days to reply. If they don't reply to Trademe, after those 3 days you'll get a refund of your fees. Leave feedback and relist.

Genuine buyers will have no problem paying before pickup, and that's the usual way for contactless transactions these days anyway.

Wow great info. Thank you so much!

The buyer and I agreed for pick up and payment when picking up the cell phone because I was flying out to a family funeral that afternoon.
I left cell phone in agreed place, I checked several times and text the buyer to remind them that I would be leaving to catch my flight. When I went to check agreed pick up point the cell phone was gone and payment not left. I have messaged and called several times but no reply. I saw on their account feedback that they were ok traders hence I trusted I would be paid. I have placed feedback on their account but no reply what can I do ?