Look at the history of Bitcoin, I believe it is not a bad time to buy, even if it is with very high values ​​I think it will go up much more value, many economists say it will be worth $ 100,000 in 2020, let's wait and see.
About Litecoin, I think it's going to drop a bit in the next few days, keep an eye out so you can make a little profit if you want to buy. Enjoy the low of it when you have and buy that will already have a profit in the short term.
Ou então Compre Métodos em cada um ou invista um pouco em outras altcoins também, como WAVES, Ethereum, Dash, Monero.