There are plenty of free options available on you tube, some quite helpful.
But in general, videos as a sole teaching method are very flawed. The reason is that the learning tends to be quite passive.
It is far better if you intersperse learning a concept with exercises that then force you to try and use that concept.
Also, for various reasons, doing the exercises on a real board and actually writing out the lines you calculate can be quite helpful to learning.
I am rated 1400 in uscf and would like to buy a DVD series. Price doesn't matter too much to me. Two series I found were Daniel King's Power Play Series and Damian Lemos' Club Player's manifesto. Are any of these good? Are there any other good DVD series?