If there is one transaction (例如只用一张支票存$4,500), cash advance fee $90 封顶是对的。That is why the offer says “The Cash Advance Fee for this balance transfer offer is 4% with a $10 minimum and a $90 maximum per transfer or check used.” No need to read too much into the word “with”, it simply explains the cash advance fee. The cash advance fee is the same as the transaction fee as I referred above. These two words can be used interchangeable in these type of offers,

如果你用了三张支票 (例如每张$1,500)，那么 cash advance fee 有可能是$180。

$108是假设 cash advance fee 封顶 $90, 加上一年中$90的利息 (大概在$18，assuming the normal cash advance APR of 20%).

Does the above explanation make sense?