what was the weight in grams ? 480 seems a bit low for such a fine item --it looked custom made --most custom items are 14 to 18 k normally -- did he check it with 10 k acid only or did he also check it with 14 and 18 k as well --higher k gold will of course pass the 10 k test --but lower grade will not pass the 14 /18 testing -- if he only did one acid test he might have done the minimum 10k grade test and said --yep it pass's for 10k (and he pays you for 10 k (41.6%) gold by weight) --when its actually 14 (58.3 %) or 18 (75%) (thus much higher % of gold content & more valuible)
if spot price paid 10 k at say 1224 .70 per oz pure gold -- at $480 is .39 of a oz of pure gold (so the item had to be close to 1 troy oz in weight)
--the item if it weighted 1 troy oz at 41.6 % purity (10 k)-- $509 .47
58.3 (14k)-- $714.00
75 (18k) --$918.52
note the $200 to $400 differance in value