HEPA bags are spectacular!!!
Breathing and health issues aside, HEPA bags are fantastic. All of the HEPA bags that I've ever tried are a larger size than standard paper. I've tried generic and Genunine manufacturer bags. This means larger surface area. Larger surface area means more airflow escape points!!! Additionally most good HEPA like bags have a plastic piece on the portion of the bag directly infront of the bag intake. So now rather than that huge dust belch directly in front of the bag inlet on your Hoover Elite bag doors, or bottom of canister vacs, as examples, below the swivel hose connection, it is nice and clean as dirt can't stick or be blown out of the bag in that area anymore!!!
Typically you would think that with the HEPA having smaller pores for the air and dirt to pass through, that the bag would choke off quicker. In my experience, the reverse is in effect!! Due to the bags being more of a cloth or synthetic like material, it's almost like the inside of the bags are knitted and possibly treated in a way that the dirt does not clog the pores near as quick or to the point of a standard paper bag or especially near to that of a Sanitaire style shake out bag.
Bag compartmentment cleanliness and overall machine cleanliness, pre and post motor filter life and motors all stay FAR cleaner with the use of HEPA bags!! Talk about saving money- wouldn't we like the vacuums filters to last longer before replacement!!!! While many filters can be washed, you can really only wash a filter a few times before they get too worn and deformed or tattered.
Prior to HEPA bags in my canister vacuums, I would have to quarterly give a machine a thorough cleaning inside and out of the bag compartment and wash or replace filters. Now I'm at the point, I can't remember the last time I had to do the tedious chore of wiping out a bag compartment. I'm sure I don't have to describe how every plastic housing bag compartment on an upright and canister has tons of nooks and crannies that are very hard to clean and almost seem to need a Q-tip or you end up cutting your hands up sometimes trying to clean bag compartments!!
The dust level created by a paper bag is much easier to see when using a gorgeous vivid color of a navy blue Eureka World Vac hard case upright, navy blue Hoover PowerDrive upright, Black Kenmore canister vacuum cleaner, etc!!! Give any of these machines a standard bag length with absolutely no cleaning to the machine at all during that time frame and then put the entire machine under a very bright light!! Now imagine if that dust amount can collect on the machine in that small few weeks period of time, what is going into the air in your home to land in your lungs, on the circuit boards of your televisions, and computers, your classy furniture, children's lungs, etc, etc.!!!
Vacuums are powerful machines pulling the filth off of surfaces whether it be the 1000's of dead skin cells shed by the human body on a daily basis or outside elements. All of that filth sits inside of a dark, warm, filthy environment of your vacuum bag festering, and breeding more bacteria, dust mites, and germs for weeks, then air rushes into those environments and we breathe that air as it is rapidly expelled back out into the room every time the vacuum cleaner is run!!! Would you want to drink water that was passed through that environment of a filth laden vacuum bag but then filtered by the thin paper???? Why breathe it, now that the technology and science is there to help us!!!
I can't stress enough in my experience how HEPA bags despite a little more costly better retain air flow in the vacuum cleaner, keep your vacuum cleaner clean, prolonging filter life, much better retention of odors, a cleaner home environment to reduce your dusting, and a healthier environment in general!!!
Also for price variation try HEPA similar bags in green and white packaging by Envirocare. I love this distributor. Try doing numerous searches on their site for various items. They are categorized different ways and I generally use the search bar for better selection!!
3 Pack Hoover S bags of this style: $3.03,
3 Pack Kenmore C/Q canister bags of this style $2.69
3 Pack Hoover Y bags $2.59
I read some of the comments of the need for dirt and germs. Keep in mind this is not running an air cleaner and not washing your walls or your floors, it's just a method to capture as much as possible the filth from your upholstery and flooring that you were using the vacuum cleaner as it's intended function to do!!! There is still plenty of filth and germs outside, in your work environments, our schools, etc. But you don't have to breathe that stuff in when cleaning your home for it linger in the air while you and your family sleep!!
http://www.discountcleaningproducts.com/Kenmore-Repl-Style-Q-Paper-Bag-3-Pk-Envirocare-p/a137.htm