hi nictan,
you could always get a more experienced friend to tag along when buying second hand stuff. Anyway, it's really up to you, the money is yours anyway. =P
GSR series are pretty decent for it's price range. Stable and delivers decent tone. Just that you've gotta be careful about the necks, GSR are made in indonesia and i've some bad experiences with indonesian-made necks ...
so please check, especially for warpage and stuff, honestly, bring someone more experienced along, even in these music shops, if you don't know how to check, you can be conned too.