There are different wordpress service types which you could go for, some dealing with installations and basic customizations whereas others offering a professional service which involves everything including making your website unique in features and appearance. Therefore, when choosing to go for a wordpress service, you should be deciding what exactly it is that you would like done in your case.
For example, if you want to have wordpress installed, you will have to look for basic wordpress service providers who will be able to take care of the majority of stuff for you for a very small fee. This is because the process is not as complex as in the case of spending time on detailed customizations.
You should keep this in mind when looking for a web development company. It is sometimes possible for you to do basic wordpress installation yourself if you are good at such stuff. You will find installation instructions when you download wordpress. If you follow every instruction carefully, you will be able to install your software and start selling in no time if you aim at setting up a webstore. But make sure you try the shopping process out to ensure there are no errors that could prevent customers from being able to complete their shopping online.