Calculate like this:
percentage 0.0199 x $25 = $0.4975
transaction fee $0.30
In the few payments my customers have made through Paypal the charges were a little less than 3%. Those were mostly for payments of $200 or more.
You have mistakenly thought that the 30 cent fee is charged on each dollar. Paypal, and merchant accounts in general, charge a small fee for each transaction (not each dollar) plus a percentage of the transaction. This is explained on Paypal's website and the fee and percentage amounts are there somewhere too.
This does mean that Paypal or CC's are not a good way to get paid small amounts. (30 cents is 30% of $1 but is a very small percentage of $1000).
I agree with BLC7. Do get a business account if you use Paypal.
I'm not saying that Paypal, or a merchant account, or CC's, are the greatest. Just telling what I know from my use of Paypal.