There are a few important factors that one has to consider before purchasing or acquiring a packing bag. 

• The pack does not have to be cheap. But not costly also. It has to be affordable but retaining the best features.
• The best packing bag, one can obtain preferably is a back pack.
• Back packs have increased in popularity and preferred as packing bags.
• Purchasing first hand packing bags can be quite costly at times and you might end up regretting purchasing it if it were stolen in transit.
• Purchasing a second hand back pack, that is in good shape, would help one save money although they are not commonly found.    
• Checking in with relatives, friends or the internet and newspapers can be best places to start looking for one. 
• Work out how much space you need by laying out an outline of things you will carry with you so that you choose the right one with the right space and alignment.