I have personally bought bags from two different companies over the last decade or so.
The first company I used is The Bag Lady 1-800-Bag-Lady
Her bags are of a high quality and on average will last for years. Last time I purchased from her we paid about $3.50 per bag plus shipping. The $3.50 per bag is not much more expensive than some of the discount suppliers and the quality is worth the extra few penny’s per unit. However, they don’t offer free shipping and you simply get eaten alive by the shipping charges.
For the last 3 or 4 years we have been using Cleaner Supply 1-800-388-5410 http://www.CleanerSupply.com Cleaner supply, cleaner supply us to produce poor quality bags 5 or 6 years ago… But they have really stepped up quality over the last couple of years and are now my preferred supplier for laundry bags. You can get bags anywhere from about $2.30 – $4.00 but, cleaner supply include free shipping for orders over $100.00 which saves you a ton of money. We are still using almost all of the bags we ordered from them 3 – 4 years ago and couldn’t be happier with the improved quality.
Either company you chose don’t forget to order bag loops and tag holders.