Should I buy it??

[aart]

Shingles? I’m about to get a new roof on my house and could use the leftover “good” ones on this

Maybe....house shingles might not fit great depending on what kind they are.
Put some 'tar paper' down first.

 

[Ted Brown]

It is a very small area, there are lots of bits of tin roofing around, check out your local used source.