Yes is unethecical, like selling drug names or porn. Many do though!
That's an interesting perspective.
Let's take a deeper look.
Defining Unethical:
unethical adjective
un·eth·i·cal | \ ˌən-ˈe-thi-kəl
\
Definition of unethical
: not conforming to a high moral standard
: morally wrong
: not
ethical illegal and unethical business practices immoral and unethical behavior
Source
The act of business in question: Adjusting prices for a digital product/property based on the consumers income, economical geography, and other value related data. Here's a 2005 case study and legal proceeding
The law and Internet pricing
In early June, the Annenberg Center at the University of Pennsylvania released a new study, "Open to Exploitation," which addressed online price discrimination among other subjects.
The study revealed that nearly two-thirds of adult Internet users surveyed believed incorrectly that it was illegal for online retailers to charge different people different prices. It also noted that two-thirds of people surveyed said they believed online travel sites are required by law to offer the lowest airline prices possible to all customers.
Not only did the survey participants think price customization was illegal, they also strongly believed it ought to be. According to the study, 87 percent of people surveyed strongly objected to the practice of online stores charging people different prices for the same products based on information collected about their shopping habits.
The report was based on results from a telephone poll, conducted in February and early March, of 1,500 adults who said they had used the Internet within the past 30 days. The margin of sampling error was described as plus or minus 2.51 percentage points.
Is differential pricing illegal?
Charging different prices to different customers is generally legal.
The practice could be illegal, however, if the reason for the difference were reliance on a "suspect category" such as race, religion, national origin or gender.
The practice could also be legal if it violates antitrust or price-fixing laws.
The federal Robinson-Patman Act requires sellers to treat all competing customers on the same basis, unless there is some recognized legal justification for different treatment. But the act is targeting anticompetitive effects -- which are unlikely to arise in the highly competitive online market.
The very bargain-hunting message boards and comparison sites that have uncovered differential pricing, also discourage monopolies. Online, an Albuquerque, New Mexico, company can undercut a Syracuse, New York, company, and vice-versa; meanwhile, new or gently-used options on Ebay provide still more competition.
Finally, the Federal Trade Commission (FTC) could get involved here if it so chose, but only to a limited extent. The FTC can police against "unfair and deceptive" trade practices. Thus, it probably has the power to regulate the type of information that can be collected online, in order to make decisions about differential prices, and how such information can be used. But I am not aware of any initiative to aggressively do this on the part of the FTC.
Source - CNN
Franchises: Interesting tidbit about franchises that basically outlines how a McDonalds in Toledo, Ohio may charge less for a Bigmac than a McDonalds does in Anchorage, Alaska. Unless there is a contract outlining a flat/cap/min/max rate across the board, a franchise is free to charge what ever they want at their respective location. Generally they are competitive and not over-priced for the target demographic they cater to in the locations region.
A franchisee controls the price of the goods it sells or the services it provides. Any attempt by a franchisor to set a minimum or fixed resale price within a franchise agreement or otherwise is prohibited. It is illegal for franchisors to employ practices that have the indirect effect of achieving a minimum or fixed resale price. Examples of such practices may include providing a franchisee with an incentive to sell at a certain price by printing a recommended resale price on the goods, or imposing penalties on franchisees who do not adhere to franchisors’ predetermined prices. Franchisors cannot impose promotional or discount prices on goods sold by franchisees. If a franchisor wants to implement a promotion, it can only do so where the franchisee has agreed to participate. Crucially, the franchisee must be free to opt in and out of the promotion and the franchisor should make it clear to customers that the promotion is available at participating outlets only. However, franchisors do have some degree of control over the price of goods sold by franchisees. It is possible for a franchisor to impose a maximum resale price, above which a franchisee would not be permitted to sell the goods, and franchisors may also provide franchisees with a list of recommended prices. Again, in doing so franchisors should be careful that they do not have the indirect effect of achieving a fixed or minimum resale price.
Source
Note: Have you ever seen the price tag on a small bottle of coke at the Bellagio in Las Vegas? I have... They legally charge upwards of $5.00 for a tiny bottle or can of coke that I can get in Texas out of a vending machine for $1.00.
I think in light of the above, price flux is common practice among businesses charging consumers sliding scale rates, so why should business to business or investor to business be any different?
What's good for the goose is good for the gander.
At the end of the day, it's business. Until there is a law to stop price-sliding in brick-n-mortar businesses, franchises, etc., there won't be one online either.
What would be unethical, would be to allow only some businesses to price-slide to take advantage of consumers, but not to allow business to business or investor to business to price slide them right back.
Just my thoughts on this topic anyways.
To each their own, everyone does things differently and sometimes has a difference of opinion.
Not the end of the world.
It's an interesting topic.