How well do iPhone trade-in companies check your phone?

I'm looking to trade in my iPhone with a company like Gazelle or NextWorth. My phone is gently used but is missing the SIM card tray. I have replaced the tray, but it is not an official on from Apple, and is missing the ID number and what not. For those who have used these kinds of trade in services (including the in person ones), do you have any idea of how closely they inspect the phones? I'm hoping they won't notice that I don't have the original tray because then the $300 price tag gets dropped to $90. Definitely not a $90 phone! Thank you.

Added (1). Well, I'm not exactly expecting to get their top offer, but I certainly don't want the highest offer to start at $90.

IPhone or Micro Sim not working?

Ok, so my old phone (an LG tablet - Service provider Orange), went through the washing machine in my shorts (I know, silly me… )
Anyway, I just got my new iPhone in the post. It seemed fine, working and all. My old simcard still works, but only has about 3 numbers on it, so I didn't bother transferring them.

I've been fiddling around and working it out, playing and so on, but it wouldn't send or receive messages or calls. I thought this was because I have awful signal at my house, but I went up the road with it, and it still says "No Service" in the top right corner.
Wi-Fi works, but I can't use my phone as a phone…

Anyway, I used the extender thing to put the microsim into another phone, and no signal, at all. I used my old sim, and it managed to find a signal, even in my house!
So, I'm guessing I have a faulty microsim, but can anyone tell me if I'm worng, or if I've managed to miss something in the setup to make it work? If not, can you suggest what I should do - I'm guessing I have to go into town and ask the orange people x.x

Do I have to give in my old iPhone to Apple?

My iPhone recently suffered water damage, Apple has offered to replace it for £119, but what I'm wondering is if I have to give in the old iPhone, or whether I can keep it.

Much appreciated.

How did i get a missed call from me on iphone?

I woke up and checked my phone and i saw i had a missed call. And i was from me. How is this possible. I didn't call my phone or something. I didn't hear the phone go off becuz it was on silent. But still can someone explain how i got a missed call from me on my iphone. I have a iphone 3G i had it since november last year and this never happened before.

How to change my NAT status to Open?

Here are some details in case you need to know:
-I use the wireless mac Airport Extreme
-Comcast is my internet provider
- I use wireless for my iphone, macbook and xbox
It is set to moderate I think? So I need to know how to set it to open because my xbox live has low connection now when I play. As opposed to my old router which was open already.