Hey, it's me again!

First off, I'm excited that the next meet and greet is going to be close to where I live, and I'm trying to figure out some good new hides in the area. I do have a wooded area very close to the house, and I hope to have an ammo can planted there before the event, and maybe even start a couple of trackables there. It's also a place pretty close that I can check on regularly.

I have a couple of general questions to ask, and I'll hang up and listen:

1. What are the key differences? I know the general idea is to send an object on a journey, and see how far it goes, but I don't suppose I know exactly where to start. Are there differences between travel bugs and coins?

2. Where to buy? I suppose that the real asset is the code numbers, but I don't guess I completely understand how that part of it works. I see where you can purchase stuff from the shop part of the website, but could you put the numbers on something you make yourself? I don't want to sound chintzy, but $15 seems a touch steep for something that I'm going to drop into a cache, and never see again. I'd consider it a small price to pay if I was more confident it was going to get somewhere, but it sounds like they frequently get ripped off by vandals or pocketed by casual cachers who don't keep them moving.

3. Where are some of the hotspots to trade and move trackables? I'm new to the hobby, and primarily hunt urban hides. So far, I've only encountered a handful of caches big enough to hold trackables, and most of them were just filled with garbage. I realize I have only scratched the surface of this town, but this part of the hobby really intrigues me.