The place or location that you can buy a cheap promotional bag for your sons would be a family owned business or maybe you can find a local business that will give you a sale everyday.
I am not entirely certain I know what you are referring for promotional bags. Are you looking for promotional bags that you can hand out, or ones that you can purchase. Try Amazon.com as a starting point.
you can buy cheap bags at http://www.everytide.com/ with a reasonable price
Asos.com has a lot of messenger bags. They also have an outlet store. Next time, define "cheap"
There are many places where one can get promotional bags for sale. One can get promotional bags for sale at popular on the web sources such as eBay and Amazon.
you can try to find out some really cheap sleeping bags online. Like searching ultralight sleeping bags, so you don't get those heavy and expensive one. Normally light sleeping bags is cheaper.
if you mean cheap fakes, then the markets in th city.
There are several places one can buy wholesale promotional products. These places include The Promo Hut, Ink Head, Promotional Gifts Wholesale, and Epromos.
You can buy cheap business objects like pens or candies for promotional events with the name of your company on it, really cheap. There are many companies that you can get those objects from.
For a restaurant business, there are lots of promotional items to choose from like promotional mugs, personalized pen and promotional bags.
Authentic vintage bags are undoubtedly the best fashion accessories to show your personality. When you are looking for such cheap vintage bags, there are many reliable and worthwhile websites like BabaReplica, AliExpress, Etsy, etc. on the Internet.
There are a number of online retailers from whom one can buy cheap evening bags. Amazon and eBay are both good places to try. Self Growth may also have some cheap ones.
Toys R Us or Target Or Walmart