Jojo...what would you like to know? I'll try and help you if I can.
I know how time consuming and frustrating it is to try and search through the forum! You can post here or PM me...either way is fine.
okay...I'll just go ahead and give it a go anyway:
The cartos on sale for $7 are the older style,prefilled with Dekang juice cartos. That means the caps are hard and glued on. The resistance is a little lower which means they run a little hotter at 3.7volts...meaning on a standard KR808 battery. There's nothing "wrong" with them and if you like that style carto the price can't be beat.
There are some first run turbo carts for sale with the hard caps. It will say in the desciption that they have the hard cap. They are bigger so hold more juice,and the resistance is higher so they run a little cooler. Most people find the Turbos last longer and may tend to burn the filling less. But we didn't like em because of the hard caps. So....
The "new" Turbos have a soft rubber cap and no glue. Otherwise they are the same as the other Turbos. The cap can be taken off with your fingernail..no tools required.

The blanks sell out fast but Ben trys to keep them restocked. Many people including myself feel they are the best quality KR808 cartos out there so far. Some people charge a dollar less....others a dollar more....but Ben offers 1st class shipping which for me evens out the price to be as low as anyone you'll find.
Hope that helps!