You can buy one without an upgrade but it will cost you a lot more money
$199 for a 16GB with upgrade, $299 32GB with upgrade, $399 64GB with upgrade but if you are planning to buy it without a contract it will end up costing around 650 like at instantsalezone.com
No, you can not upgrade your iPhone 3G memory.
$199 for a 16GB with upgrade, $299 32GB with upgrade, $399 64GB with upgrade but if you are planning to buy it without a contract it will end up costing around 650 like at instantsalezone.com
Yes, you will have to be eligible for an upgrade to get the Black Friday deal at best Buy on Black Friday 2014.
Yes
Could be you just want a iPhone on prepaid
Ebay
yes. eBay.
no
you cant upgrade without paying but you can buy the upgrade online instead of going to the store
yes
http://support.apple.com/kb/HT3406