Tamron 17-50mm f2.8 lens with focus issue- is it something worth selling?

Hi,

I have a Tamron 17-50mm f2.8 lens that has developed a slight focus issue- sometime it doesn't focus perfectly. I bought a replacement/upgraded it.

So what to do with the lens; is it something that some people would be interested in buying for spares or try to repair it themselves? I've no idea. If so, what's a fair price?

Cheers,

Pa.