hrm, it's every hard to say which are acceptable and which are not. some coins are premium over the other like for instances the panda coins are always more premium over eagles and maples. same goes to those australian lunar coins. so far, i've noted for coins with face value, the eagles and maples seems to be are the lowest among the rest. apart from that, you also have to consider you buying the coins from 'premium' dealer or garage dealer. of course, premium dealer have higher spot price while ebay have lower. for us, we also have to consider the importing cost as well. i guess there are no prefect answer to your question. it's a matter of preferences 

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