most extract prices are ripoffs so therefore its waaaayyy cheaper making your own and also fresher extract is a lot better just make sure you know what you are doing. fist find a cheap source of leaf
I know where to get a lb of leaf for $100
that would be able to make 2 ounces of 8x extract and trust me you dont need to go higher
to go beyond 10x you need to wash the waxes and tannins from it so you dont end up with unsmokable material its called standardized