the risk level on Bitcoin as well as altcoins is lower than ever before. And the prices of altcoins are moderate, in fact they have not increased remarkably relative to previous years.... Does it mean that it is right time to buy or that this right time is near ?
I understand that you are assuming like bitcoin is currently lower than 100k levels hence the risks are reduced and you consider the current prices are right time to enter. All I like to mention here is, you need to study about the fundamentals of bitcoin and it probable upside potential. This way some people believe that bitcoin may touch 1M level this year whereas some people people 150k or 200k levels for the same time span. In my opinion, in long run even 10M also possible but for next year or for next 2 years, I am with fingers crossed. So, it may be early or right time to buy bitcoin (not whole cryptocurrencies) with respect to how long that you are going to hold.
if you're really care about risk/reward ratio, then just wait until bearish cycle comes in. it's as easy as that.
This way, you may miss the upcoming bullish market (if any). This is the reason, DCA may help you better than waiting and then all-in-at-once.