Hmm... I kind of question some of the tips listed there. They may be possible for smaller companies, but many major companies (especially ones located in Korea) have policies NOT to allow specially customized orders in case people start taking advantage of that and things begin to get out of hand.
Actually, now that I re-read it over, these tips sound like ones that'll work great for
2nd-hand dolls. I have noticed that unstrung dolls tend to sell for cheaper in the DoA market (although I've only seen a few examples of them), seamlines and aged resin will definitely allow for more haggling room, and refusing the company box will actually lower the weight of the package leading to cheaper shipping costs.
Still find it a little difficult for major companies.
Well... There's no harm in trying it, I guess. The most the companies will do is give you a rude reply (which most of them probably wouldn't for the sake of business)..?