Forum Moderators: buckworks
I've read 100 postings where people say OSCommerce is a good start, or X-Cart is a good starting point, but then you have to customize from there.
I haven't read too many postings where people say they had a cart developed from scratch for their exact needs and if it went well or not.
I have one customer who initially developed a series of real estate sites that offer all the usual stuff, with a free personal web page for each member, and a networking system between the sites. Although it's not a "cart" per se, it's an indication that a site that grows and evolves is never really done. As he gets new ideas for features and benefits, all the sites evolve accordingly based on the original programming. A good ecommerce site (IMO) would have the same evolution, so a customized shopping cart is never really "done" in that sense.
On a personal level I've developed a cart and administration system for my wife's site customized to her needs. I've been tweaking it for the last couple years, adding this or that as she needs it, but the core functionality has been reliable from the start.