I think this is not a good idea for you if this time have to buy bitcoin at a very high price except for trade or investment, for fear the price will experience a decline will certainly lose.
The possible decline on the price is just a temporary lose for your investment because the price now will not matter after 10 years of holding bitcoin. If you buy bitcoins now and hold it for long term then the price now compare to the possible price in the future will not matter because the price in the future will be extremely high.