The average internet entrepeneur grossly underestimates the time and money investment required to start a webshop in a proper fashion.
There is a plethora of reasons, but the main reason is a lack of analysis before starting implementation. Get informed as an e-retailer: know the possibilities and limitations of e-commerce and the different e-commerce software systems. This leads to more understanding with your implementation partner and as a result less communication overhead.
The most useful information for an implementation partner is to have a clear idea of your demands and wishes and write them out in a detailed specification. An independant e-commerce consultant can facilitatie this as well, or larger companies may employ an e-commerce manager. By getting requirements clear before choosing an implementation partner, quotes of different suppliers can be compared easier and the quotes’ required budgets will be less.