Hey buddy, I hear your problem, my family doesnt follow it either, although they dont appear to be as hostile as yours.
the truth is, alot of the older generation just don't like change. My advice would be to stop trying to convince them to change. Focus on making the changes you can make to your own diet.
In terms of evidence, it really depends what your trying to show. You wanna sell the concept? get the book? you wanna show that fat doesnt clog arteries? There are articles for that. But even if you figure out what you want to prove, is any amount of proof gonna convinve your dad to change his ways?
People can only really motivate themselves to change, yes it can be sparked externally, but on some level they need to embrace the idea, because they recognise the benefits they are going to get out it.
In terms of cost, primal doesnt have to be expensive. There are loads of pages about budget primal about.
For the wash/shower products etc. i find avoidance is more powerful than cleaner alternatives... I mean, only use the minimal amount of stuff you have to. If you got a good diet, a few pollutants in soap will be ok for your body to deal with. I personally wash only with water, and rub my skin with a sponge. (brushing off the dead skin cells and dirt at he same time). My diets fiarly clean so my body doesnt pump toxins out of skin and I dont smell etc. I use regular toothpaste, just not too much and never swallow, I could go on with these details but you get the picture.
below are my links to budget student paleo tips and issues for teens