I changed mine a couple of months ago using the same helpful video!
From what I could see, I think I bought the same filters James used, Blue Print from the usual auction site for around £10 for 2 required filters, significantly cheaper than Tesla OEM.
I weighed the new Blue Print filters at 155g each and the old OEM was 208g. Yes it had some dirt on it, adding to the weight but it wasn’t heavily soiled. If you do weigh your filters using the kitchen scales, make sure you clean it up before your better half sees you. I think I got away with it.