Just bought the Costco (Canada) box again this week. I've used these in my class B, motorcycle for touring and my sailboat, all of which have limited storage space. Works great for me, and I've had stuff in my boat not opened for at least 2 yrs.
Also use double lock strip or zippered Ziplocs for a few items, including some food items and just suck out the air as best I can. Helps some foods stay fresher longer, (cheese comes to mind here).
PS just looked the Costco box I got has 15 bags, 4 med, 5 large, 12 XL and 4 "travel valise" size. Dont' recall the price but it's cheap for my needs/uses vs the benefits and quick to use as well.
Calgary, AB Canada