You don't launch a store, online or brick and mortar, by quoting way over priced prices with the comment or viewpoint of offering specials later down the line. Customers are neither patient nor stupid. They will give you a chance from the get go- and that's where you need to impress them. Later on will never happen as you will not even be thought of as an option when compared to existing stores with great service and very competitive pricing already being offered. Rather focus on a niche market or range and do that 110% better than anyone else.