There shouldn't be a problem with submitting from 1 domain. Just check with the sites you submit to to make sure it's alright.
Also, consider looking at some other submitters that don't charge a monthly fee. Sometimes a 1 time fee is the best way to go. ..Especially if you have certain sites you submit to that will not accept the auto submit feature. I'm a fan of semi-automated submissions where I can actually see the info being filled out to avoid blacklisting.
