The price might get high but the liquidity goes on no matter what happens because the increase of the price doesn't just mean that everyone is holding it some people are actually using it as their means of payment. Some other sites are accepting it and most of the gambling sites still use BTC as their tokens. so, there is no reason for the liquidity to fall short and besides, more of those known companies are trying to get their hand on BTC to make their company flourished even more. Liquidity will not be subsided at any cause you just need to look at it the other way around.
Less available bitcoins on exchanges do not equal to less bitcoins available to be sold out in one period of time. Whales, institutes, small investors only move their bitcoin from exchanges to their own wallets for their safety. The movements are preparations for future sellings. They will sell their bitcoins somedays at the price they are planning to take profits.Another flaw of this liquidity crisis theory is people can still have enough available bitcoins in market, on exchanges to buy and sell, to change hands every day. I am thankful to the guys who made the theory on media that help bitcoin price to begin its parabola and made it looks more scarce in supply.
The supply is very limited and because the demand is rising fast it is inevitable that there will be a smaller amount available for buyers. But no one is required to buy large amounts or full Bitcoins. People may buy Satoshis if they cannot afford a full Bitcoin.
Liquidity is different than supply and you are correct that people can buy any increment of bitcoin from their fiat available in pocket. 
