Yeah I always prefer bitcoin as compare to altcoins and for me  you can afford to buy now with some bitcoin with the current price of course that would be better and hold it for long term to have a good profit. But if you don't, best time to buy altcoin now as some of them are crashing, this is the perfect time to buy. However, buy the potential coins that you think that over time will pump. Soon altcoin will rise again so better now to don't have regrets.

You can also invest in altcoins but before investing in altcoin, just make sure the altcoin that you're gonna buy are legit and and listed at the top 20 coinmarketcap. Like xem, waves, bay and maid also eth.