I take it you are not in the US?
As mentioned we are expanding and the 10% can easily be avoided with our membership.
I am not, and most of the members I talk with in forum are located in Europe.
Membership is ok to save on fees but only for people who are ordering stuff from amazon all the time.
I am not aware of anyone else that offers this service, do you have a link to the monero option you mentioned?
The only other ones I know of use gift cards or even fraud, its cheaper yes but as you mentioned it comes with its downsides.
One of the services I know is monezon.com that works only with amazon.
Another service anonshop.app is similar but it works with other platforms also.