that's the tip of the iceberg on product testing. but in the end when you find what you're happy with it'll get easier / cheaper.

I've been detailing part time for the last couple of years. I'm still learning huge amounts. product developement and evolution is pretty big and can be costly to keep up with. one thing i find is if i buy a product and test it and don't get on with it after 1 or 2 applications you can sell them on. i know that this is a tad mad but you can regain some costs this way. also if you are looking to move into detailing full time one thing i'd say is when you find products you like, try to become and approved reseller. this way you can get the products in at trade price rather than having to shell out full price for them