Quoted from Lermods:Buy a small spray bottle, fill it with a 50/50 mix of ipa and water. Can’t get much cheaper than that, lasts a long time.
This. Mixed some up in a Home Depot spray bottle a few years ago after I got my first sheet of PDI and have been using it with a microfiber cloth ever since. I use it on all my games and I have only gone through about half of the original bottle. Works great and lasts forever.