there are other shop modules like CataLook, Sysdatanet, AliCommerce and ETailer Shop, have a look at www.snowcovered.com. All seem to have advantages and disadvantages in functionality, usability and ML support.

Sebastian (as always) talks a lot of sense. You need to evaluate what the shop needs to be able to do and then make choices.
 
 If you do not have full trust privileges in your hosting package then it may be worth checking that you choice can run under medium trust.
 
 I use eTailer on a couple of non public, lightweight members only shops.
 Its simple and admins can deal with it.  The Ajax is really nice and the ability to easily add variations to a product saves a lot of time.  Its well worth the $40.
 
 Catalook may well be able to do anything but in many ways its "solutions looking for problems".
 8 hours ! ?
 
 I have to make an e-comm only site for a client soon and have come to the conclusion that the most efficient way is to go over to the dark side (PHP) and buy something like Cube-Cart.
 
 From any sensible point of view it is not reasonable to spend more time on something than is needed to deliver the required features especially these days. 
 
 The other angle to this is if the shop is not busy all the time then a dnn site will shut down and so increase customer load / frustration times.
 
 good luck with this.
 
 Ian