How to buy Second Hand used tech

Hey guys, there is a big problem with used tech, nobody wants to buy because:-
-it can go bad without warranty
-you can get scammed and buy a broken device
-you just have no idea how was that device used or, it was put in strange places!
1 if you buy a second-hand device you have to make a good deal you pay 1/6 of the MSRP.
2 you have to know the regular issues with that specific device.
3 you clean with 99percent alcohol over and over again for a maximum of 10 years just if you are not sure. just to be safe.

                             Let's find a case for the first buy.

1 why you need something second-hand - cheap ( 0 warranty ) MSRP 1/6 so you can buy another 5 and you can destroy each it will take more than the 1 y warranty or even 2.
2 why never get advice from mediocre people against buying a second-hand device? because they get scammed all the time because they are not very smart and they cannot identify a fake from a genuine, they don't negotiate, they always get a bad deal and then they cry and buy new and get fucked again.
3 remember when bitcoin was cheap was bitcoin bad not functional broken dirty? probably if you are stupid that may also be true. So try to find the good value and start negotiating, develop skills and use them to get good deals and then get better deals.
4 try to find out with hu you deal, if is an Indian guy that has the best and the most beautiful device that is hard to get, please forget about that person. And I don't like Indian scammers is true :) is full of them everywhere. And yes they are smart.
5 ask for the phone number and contact the seller, note how long it takes to give the number after a past message just received, and note how long it takes to answer. If it takes to long the deal is off as they are not happy to deal with the trouble if is a small value. Usually, nice people like to give all the information requested. Scammers like to pretend that they don't know as is better than to lie to you, or to start making stories, if you pay attention you will spot something.
6 when you get face to face to close a deal make sore you don't pay before you see what you get and then start checking.
if any defect visible was not specified and the rest of the device was covered don't take the deal without a good discount if no other issues can be found.
8 pretend you know what you do, when checking a device and ask questions, usually, scammers have an answer for any issues if they are real or not, they don't know what they sell most of the times. Sometimes you can take a bait also.
7 after inspection look at the person ( seller ) if they become agitated, in a hurry say sorry an let them go.
And if every spot is a clear move for the purchase !!!

Now you can go back and find another 5 devices that can be bought for the left money.

My story

I Buy usually underrated devices like : *PS Vita 80 usd can be sold as pwn shop or CEX for 110
*HTC M8 . 80-100 usd can be sold with same price
*beats any 1/6 of the MSRP if in good condition
* Ipad 300 is the max for 4 g ipad air 128 gb and you never need a better iad
*Try to get sound systems from Logitech only as they are good they never brake.
*Old TV are worth nothing 100 inch TV 10 y + don't pay money if you really want
*30 40 max the seller needs to recycle and will sell, put in the bin, he will be cool.
If you are not sure and is big value item go to the CEX or pown shop with similar item from a friend and ask them how much they offer for same, and add 10/100 to that ussualy sellers go there before and that is the minimum they will ever accept.

If is low value try to go as low as humanly possible and hope for the best, With this technique you don't have to buy something when you need you can buy in advince as your budget is good at all times.