Few people do it but generally all discounts are available if you ask for them. I've had luck calling or e-mailing customer service for the company I'm thinking of buying from and simply asking for the best discount they can offer.

If you are willing to go to the trouble of asking most companies are willing to make the effort worth your time to make the sale and gain a customer.

Bargaining, haggling, and asking for discounts isn't just for brick-and-mortar stores. Work those customer support people. Ask for their boss if they are unresponsive. Be polite and upbeat but get the discount/s. Discounts because a retailer may offer a discount and the manufacturer another. Remember that mark-up are typically 50% to 80% of the asking price.