Preps don't have to break the bank.

Buying high quality gear is important - your life, safety, etc. may depend on it one day - but that doesn't mean that all of your preps need to be bank breakers. Some of the most useful preps can be had for a couple bucks at the local store. Here's a few:

• Bleach: Unscented kinds with no additives; just plain ol' bleach. Good for purifying water and sanitizing in general. Rotate once a year. 
• Calcium Hypochlorite: Sold by pool stores; add a heaping teaspoon to 2 gallons of water to make a bleach solution for purifying water and sanitizing. One part solution to 100 parts water and wait 30 mins for purification. 
• 5 Gallon Buckets: Carry water, store stuff, make bucket planters, sit on 'em, crap in 'em (but not all at the same time).
• Contractor Grade Trash Bags & Drum Liners: Shelter, add insulating materials for a improvised sleeping bag, gather water, carry stuff, use for trash, blackout windows, add duct tape to seal a broken window.
• Duct Tape: It has a light side, a dark side and binds the universe together. Uses are basically limitless. I prefer stronger Gorilla Tape.
• Freezer Ziplock Bags: Gallon and quart size. Multi-use; store, hold water, etc. Can be used for SODIS.
• Candles: Light + heat; Ikea has jumbo packs of tea lights for a couple bucks. Wax has its uses, too.
• Tarps: Shelter, privacy, haul stuff, catch rain water
• Staple Foods: Bulk packs of rice, flour, wheat, sugar, oats, pasta, etc. Eating is good!
• Super Glue: Repair stuff and seal cuts.
• Matches: Bulk packs of matches are dirt cheap - you can get a shocking amount of matches for $5.
• Lighters: Bics and Scriptos are good fire starters.
• Toilet Paper: Aside from wiping, makes decent tinder.
• First Aid Supplies: Gauze, bandaids, etc. 
• Cotton Balls & Petroleum Jelly: A few bucks and you can have scores of effective fire starters. Both are multi-use as well.
• Rubbing Alcohol: Sanitize, start fires and fuel pop can stoves.