if you are talking about something like lelong.com.my forget about it if you are paying 4 digi .... this site min also 5 digi already... but if you are looking for simple one like goldfries say oscommerce will do .. normally ppl charge cheap confirm they are using opensource to do for you already ... if not you can ask some company have their own ecommerce product they are charging around 3k+ for a basic one, other feature that you request will be addition charge, now a days no ppl will count how many product you have is all unlimited product