I completely agree with the other two contributors. I also want to add:
The Battery Cycle Count is not an indicator of battery health. The only time it has any meaning is when the cycle count is high....nearing 1,000 cycles. If the previous owner always kept the power adapter connected, then the battery will have a low cycle count. Age of the battery plays a bigger part in battery health. A three year old battery is getting near the point where it may be starting to wear out or fail. I find batteries need to be replaced around 3 - 5 years old. Unfortunately many battery failures will go undetected by the Apple Diagnostics, macOS battery condition status, or cycle count. An official Apple battery replacement is typically about $250 US, but you can confirm by checking the Apple article here:
Mac Repair & Service - Apple Support
Another concern is whether the pre-owned Mac has been properly prepare for sale. So many people post on this forum about finding out their pre-owned Mac is still being managed by the previous owner or the Mac has been locked & is inaccessible. It is recommended to only purchase pre-owned devices from reputable vendors, or possibly someone you know & trust although the latter I find can still be a problem as you may discover they are not as trustworthy as you thought. Here is an Apple article which describes everything the previous owner should do before selling a Mac:
What to do before you sell, give away, trade in, or recycle your Mac - Apple Support
Even if the previous owner has done all these things, I highly recommend people perform a clean install of the OS by first erasing the disk followed by reinstalling the OS (starting at Step #6 of the linked article). This can sometimes reveal issues with a pre-owned device which is an additional reason why I recommend it besides having peace of mind it was done correctly.