Yes, now is a good chance to buy all kinds of altcoin, but BCH prices are not down, and they are always uncomfortable.It's worth noting, however, that some of the altcoin developers have disappeared, and be careful not to buy such altcoin!
I do not think it is a good time to buy all kinds of altcoins, I do not think all the altcoins are promising, but some hot projects like avt, amb are worth to buy since the price are below the ico price in my opinion.