I will not say you must do this or you must not do this.
Every person is different. 
I can say from my experience I notes following 
   = People always give priority for products with free delivery
   = you can include the delivery cost to the price
   = but price need to be competitive
   = Always research in SFI as well as other websites such as ebay price range
   = If it is a special item rarely available online to buy,  try few items at a   
     reasonable price 
   = If you have large amount of same product try few at a time to see the market
   = some products only target to specific local area. those products you better to   
     advertise only in local markets.
   = learn from experience that is very valuable rather than someone else advice
Good luck with advertising
                                            
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                    I will not say you must do this or you must not do this.
Every person is different. 
I can say from my experience I notes following 
   = People always give priority for products with free delivery
   = you can include the delivery cost to the price
   = but price need to be competitive
   = Always research in SFI as well as other websites such as ebay price range
   = If it is a special item rarely available online to buy,  try few items at a   
     reasonable
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