With private key you can access and transfer the tokens anytime. If you buy an address with private key, both the buyer and seller have access to the tokens. Anytime, seller can access the tokens and transfer. So, It is not feasible to trade addresses. Don't buy addresses.
True, and also more.
The seller can sell the private key a infinite numbers of times.
And any buyer can become a seller and sell the private key or JSon file (or other wallet access) a infinite number of times.
This market of wallets access is a market of scameur, even with a escrow :
DON'T BUY A WALLET : YOU WILL LOST ALL YOUR MONEY !.
If you want buying MNE, buy only MNE (20 MNE per transaction at this time, 1,84 MNE more per day for the future).
My two cent...
... but if you want absolutely a wallet access, I can sell mine for 1 BTC :
- I'm honest, of course, but how can you are sure ?
- Even if you are sure that I'm honnest, how can you be sure than in 2 months, 2 years, 20 years, 47 yeras I will still be honnest (a private key cannot be changed and the wallet will mining 47 years) ?.
I hope that you have understud : glad for you.