For me personally and because i am quite anal retentive when it comes to having a "safe" motorcyle so tend not to take the easy cheaper options, it would be new tyres for me everytime.
examples of my retentiveness;
Advised brake pads are approaching wear marker : Had new pads fitted
rode my bike (until the sudden stop) out of my garage forgetting the disc lock was on, no apparant damage to the disc : Had new one fitted anyway just in case
at the end of the day its about peace of mind i think