A short while ago I went to a fancy restaurant and had 'deconstructed cheesecake' for dessert. I received a small plate with a blob of cheese, a line of graham cracker crumbs, and some loose, sloppy whipped cream. The dessert, as far as I could tell, was the chef's excuse for not using a springform pan!
The Celts used the same basic 'deconstructed' approach to the patterns on this coin. Usually you cannot discern the likeness of Apollo, but with this example from Ira and Larry Goldberg it is possible to make him out. The reverse side shows a deconstructed warrior driving a chariot.
There are 1/4 and 1/2 staters, but full staters weigh about 6.5 grams with diameters around 20 mm.
As to value, these coins stand on their own merits. It is basically impossible to assign catalog values, so the listings below give very, very approximate guidance based on CoinQuest's analysis of 2015 auction results. If you have a nice example, be sure to seek out a professional.
worn: $500 US dollars approximate catalog value
average circulated: $1000
well preserved: $6000
As with all valuable coins, fakes are all over the place. Never spend a lot of money on coins with someone you do not trust implicitly.