This time is very crucial for the whole world due to COVID. Not only crypto the whole ecosystem is down. It is not about only you should invest in BTC you can invest in other cryptos as well which you think gives you good returns in the future. You can buy small amounts of the coin if the budget is a constraint. Stay safe and happy trading.
Depending on where you located at and including your current financial health for investing, COVID-19 does make you think not twice... maybe even thrice... because nothing is still certain until the pandemic concern has been resolved to a certain extent.
It's a good suggestion since like what you've said "you can buy small amounts of the coin if the budget is a constraint" indeed. But always make sure you that you have a back-up plan already, in order for you to avoid selling your crypto and avoid incurring unexpected losses as well.