I do not think there is any reason not to invest whenever you have found a high quality project, i mean even if the market situation is not good if you invest in a good project that will definitely give you returns sooner or later, so go for it.
Yes, it is good time to buy or invest on ICO, the price value are affordable. We can choose good coin with clear market structure, good fundamentals, with support system inplace, but one should always remember the risk factor involved in investment. I suggest invest only what you can afford, money which is not committed. Good luck guys.