Depends on your objectives. If you're not preparing for the apocalypse and you're not 100 miles from the nearest trading post, it comes down to cost.
First thing I did was decommission my 1970 freezer. That saved more in electricity than I was saving buying items on sale.
My quest started with wanting to save leftovers so I didn't have to overeat or throw 'em out. I picked up a foodsaver at a garage sale. Got it home and got severe sticker shock from the price of the bags. I'd have to spend 50-cents on a bag to save 30-cents worth of leftovers. There's a reason why every other garage sale has a foodsaver.
I went on a bag quest to find a way to use cheap bags.
These are the conclusions I reached.
The sealing systems work by reducing the volume of the space surrounding the food. If you can get the bag to conform to the food, the pressure is irrelevant. If you leave space, vacuum just makes it easier for the water to escape into the void.
Best vacuum I could get from my low-end foodsaver was about 20". The commercial ones claim very much lower pressure. If your bag contacts the food, more vacuum won't help.
So, how do you get the air out? The foodsaver clamps down on the bag with the open end in the vacuum chamber. The EXPENSIVE bags are made with a pattern that leaves tiny channels for the air to get through. Not only does the air get past the clamp, but it also gets past the food so you get the air out from the other side of the subject item.
If you try to use a non-patterned bag, the clamp on the foodsaver seals off the bag and you get no suction where it's needed, inside the bag. There are a couple of ways around that. You can cut up an expensive bag into strips that you insert into the opening to create that path past the sealing mechanism. That actually works pretty well. If you extend the strip the full length of the bag, you can get air past food that isn't too liquid. For liquid food, like meat that has 15% water added, it can help to freeze the food before bagging it.
The commercial sealers have a thin vacuum tongue that sticks into the bag and is automatically withdrawn as the seal heat is applied. Best way I've found is to skip the bag sealing mechanism altogether and just use the vacuum pump.
I got an impulse sealer that is open on both sides.
I seal all but a small corner of the bag. Stick a vacuum tube way into the bag to get the air out of the bottom and slowly withdraw the tube. Try to slam the heater down on that corner as the tube exits the bag so not much air gets back in. It's cumbersome, but works pretty well for non-patterned bags. If there's liquid involved, the whole thing becomes quite a mess.
If you have enough counter space so you can leave it out... And you don't get anxious about the cost of the bags... Foodsavers can be quite convenient. I'm sure you can create a scenario where they're cost-effective. I couldn't in my situation. Good thing they were all dirt cheap at garage sales.
The secret to a happy life is low expectations. If you redefine freezer burn as a condiment, you don't have to worry about fixing a problem that doesn't exist ;-)