As any other asset with high demand in China, if there is a high demand the prices go up. Simple like that, supply/demand.
Once you contact any seller in Alibaba you will note the price is not as listed, you need to open a conversation with them and after that you will get the real cost which is around $5K (S9 and PSU) and rising as long the Bitcoin madness. For any vendor, you can get a better price based on order quantity and your trading skills, do not forget Chinese culture about business (which lead to environment disaster but they do $$$ so they don't even care about it), money is money for them.
Right now from my research I noted there is plenty of S9 in the streets (measured in thousands) but highly overpriced, if you are looking to invest in a few Miners you should evaluate your investment vs what you get, for example a $5k investment in Hashflare will give you more TH power than a single S9, if you do the math including the fees and maintenance cost... you should go for cloud mining instead of paying an over priced asset for a better result in the end. You can get scammed later that is true but you can also in Ali so do your diligence and look for good options in cloud mining. I personally believe Hashflare is a very good option with 1 year contracts. In average 1TH cost $220 in a year contract - fees. For a $5K S9 you are getting $357 by 1 TH and you still have to deal with fees from the pool you select (if you get the S9 them go for pool with shared fee for transactions, due the high volume {specially on panic} sometimes the block reward can be as high as 30+ Bitcoins instead of the 12.5 for the block itself, so try to get a piece of that portion too), also the lifespam of those machines average the 1 year with good care of it.
If you are looking to spend a huge amount of money and get a mid sized farm, it is another story for you but for small operations you should get a reasonable price for the S9 if not then go for Chinese cloud mining as like it or not, they have cheap power cost, cheap miners and cheap operations so they can bet anyone at the moment due under the table business (not confirmed but really suspicious) with Chinese Government for even cheaper electricity rates and some very dark support.
PD: have you ever think about China ban to cryptocoins but not to cryptomining and the bigger miner factory only accepts crypto payments? Bitcoin Cash have a recent huge PUMP due Bitmain offering a new S9 Batch for shipping in March so this madness made the huge miners to exchange to BitcoinCash to get a portion on the batch and some price manipulation from China and Bitmain. Let's be honest, in this not regulated crypto world if any of us has that potential... we will do it.
To be honest, for the time another company build a better hardware for the mass Bitmain will have an Ace under the Hand ready to be played (new miner maybe S10/S11? cheaper batch?).
PD2: you can use my referral link to Hashflare if you think my analysis is for good value. I will really appreciate it. There are a lot of cloud mining services with a lot of options, but I personally believe hashflare has the better options with 1year vs Eobot with 5year contract. Why? you have no idea what is going on in 5y from now so in order to have a decent hash power now you will need to invest hard. What is the good part on Eobot vs hashflare, Eobot allows you to mine much more coins, so you can actually do some speculative mining and accumulate some undervalued coins that can be valued in the future, so you mine a few and hold. You can hit the jackpot in a mid/long term but for short term, as I said before, you need to invest hard.
HashflarePD3: have a look at Envion.org, google it, get involved and read a lot. Real people doing something to fight the China control and bring back decentralization to mass minimizing the impact to the environment, it has a huge potential. Recently they have big announcements about sponsorship deals and business deals for coming operations and power demanded for it (pretty much they have signed a LOI for 400MW contract with one of the biggest firms in power business in the US, 400MW!!!!! can you imagine how much hash power is that?). They are Swiss based company focused on renewal energy. Good prospect for me. I just bought some tokens too.
PD4: haters gonna hate. I don't care as long I have my own criteria about the crypto world based on my OWN analysis and thinking.
PD5: to anyone, if you want to contact me for an honest conversation for a CostaRican geek who have done a lot of analysis, just PM me. I am into mining consequences to environment and we need to do something, if not China will burn the hell of the world for some $$$ as their supply is based on Coal. As we say in Costa Rica, think green. It starts from you picking some trash from the floor and a change in the mentality.