1. Look for verdigris and general toning. - this one looks to have quite a bot of verd or dark uneven toning on the obverse.
2. Look at the band in the king's crown - this one has 8 pearls with the second pair showing some wear.
3. Look at the general field of the obverse, are there any significant scratches/indents? - this one doesn't look too bad although there is quite a few scratches.
4. Look at the rims on both sides - this one seems to be free of rim nicks, other than that at approx 8 o'clock on the reverse.
5. Look at the beads and scrolls on the reverse for wear (a weak strike can often look like wear so be careful.
This particular coin probably has detail to gVF-aEF on the obverse and around VF on the reverse. Because pf the undesirable toning and or verd I would be more comfortable calling it VF-gVF overall. I think retail it might be around $5.