I have two bags, a Get Home Bag, and a Bugout Bag. The GHB is a
RUSH 24 from from 5.11. The BOB is a
RUSH 72 from 5.11. But neither of those bags will meet the OP's price requirement. However, they are useful for illustrating the different types of bags.
Most of us are just thinking in terms of getting home from wherever we happen to be when the sewage hits the air circulation device. That means they need a GHB. If you're at work, and you have a family, you're not going to bugout from work and just abandon your loved ones. You're going to try and get home first. So what you need is a bag that will support you for up to 24 hours. Most of us, even the infirm ones, could log 20-25 miles on foot in one day if we
had to, and 45-50 miles if we kept going for 24 hours. It would be hard, but feasible. Doing the math, and figuring an average pace of 2.5 miles/hour with a 15 minute rest at the end of every hour, that's 19.2 walk/rest cycles, times 2.5 mph equals 48 miles in 24 hours. A half mph faster pace nets you 57.6 miles in 24 hours. The point is, for most working people, a 24 hour GHB pack has
more than enough capacity to sustain them long enough to get home from work on foot if they ever had to abandon their vehicle. And unless it is a complete piece of junk, almost any halfway decent smaller backpack is going to fit the bill. I like 5.11 packs because they are REALLY well made and rugged, but I'm sure that there are a lot of less expensive bags that are more than up to the task.
But bugging
out is a whole 'nuther level of crazy and hard work. I'm not trying to sound snobbish about it, but frankly, a pack costing less than $50 is not likely to be able to be well enough made to carry enough weight, long enough to sustain life, for an extended length bug out. One of the things I like about the 5.11 RUSH packs is that they have an accessory strap system called the
RUSH Tier System that allows you to piggyback one of their smaller packs onto one of their larger packs. Here's an image of a RUSH 12 piggybacked to a RUSH 24. But I can do the same thing with my RUSH 24 mated to my RUSH 72:
I can carry a ton of stuff that way if I had to, but that kind of scenario is really a last-ditch survival thing for when beating feet into deep woods and tall grass is the only rational option. It would be my hope to never need that full capacity, and if it were necessary, then one or the other of our 4WD SUVs would be the better way to get out of Dodge. In the meantime, my 72 Hour pack makes a dandy travel bag, and my 24 hour bag is my EDC bag, with a mind to just getting home from wherever I happen to be when bad juju happens.
That EDC pack contains a small food supply, water, a filter straw, a mini stove and fuel tablets, Bic lighter and an alternative fire starter, a Toaks titanium cup, some tea bags or instant coffee (depending on mood), an ultra-lite canopy/shelter-half and ultra-light tent pegs, three extra 33-round Glock magazines full of 9mm ball, my personal IFAK, a spare flashlight and spare knife, knife sharpener, small notebook and pen, a small toolkit and a multi-tool, spare fold-up reading glasses, rain jacket (depending on season), puncture-resistant gloves, a small cheap pair of binos, any portable electronics for the day, like my iPad, and small miscellaneous items. It stays in my car most of the time when I'm out and about, so it's not like I carry that stuff on my person all the time.