Their goal may not be a short-term base as most people still consider 60k Bitcoin price as a low price considering how long they intend to hold their Bitcoin, so El Salvador may decide to buy at whatever price at the moment.
That's definitely correct. In some news articles I have read some 5 year plans. For example they are building Bitcoin City and a lot of other infrastructure that won't even be completed in short term.
Besides El Salvador is among the poor countries but about $60 million in bitcoin for a country with $25 billion GDP (0.24%) doesn't look that big to be honest.