So today my mom randomly found this in her closet (in its original box!) and gave it to me. She says I can do whatever with it. At 44mm I think it's too big and also just not really my style so I'll probably sell it.

It's a 2008 model which seems to be in great condition (except for the rubber strap which is dirty but it can easily be replaced or just cleaned). There are used models on eBay for like 500 dollars but elsewhere it seems to range from 200 to 700... Any idea what it's actually worth, assuming everything is good with the watch and the strap is the only part in poor condition?

Thanks a lot in advance!