One cheap kit - Per one rifle or pistol caliber. Survival Apps.
I have seen them sale priced as low as $20.00 & Change.
Or if you want to save your factory ammo for some future "rainy" day. - and you have spare time on your hands...you can sit around for a while and reload 50 for range practice. Slow but steady will get you there and save you some $$$.
It is possible to reload useable good quality ammo with a really minimal dollar investment even sitting in the cabin and by candlelight.
Lee Precision, Inc. Reloading Tools and Equipment: Classic Lee Loader