This [super fun, pretty great] song can interpreted in a couple ways.
(1.) The singer's relationship is going very well. They're happy and he's ready to ask a big question (which is suggested by his 'down one knee' lyric and 'time to say it out loud'). This would typically imply a marriage proposal. However, it may be another big question: 'Will you move in with me?' The singer (Joe) re-words this question as 'Would you pay my rent?" (which I love for the odd sense funny honesty that his version of the question brings).
HOWEVER there is one word that convinces us that Theory Two is more likely.
"BUT would you pay my rent?"
(2.) With the inclusion of the word 'but' we now have Theory
Two. Joe's relationship is going great and he is in fact ready to propose. He loves her immensely and would do anything for her. However, there is one thing he needs to know. If times get tough and his music career flops and he's left with nothing, would she still stay? Would she literally pay his rent? Would she invest all her love - and even money if needed - in this relationship (get your love well spent)? I love this interpretation as well. It has that same sense of odd honesty that the first theory does.
As for "How can you love me right, love me right, If you don't get your money right", I believe that the meaning can be made more clear by adding a question mark like so:
"If you don't get your money right?"
At first I thought 'right' was used as in 'correctly'. However, I now think it means 'Right?' as in 'Do you agree?'
This potentially is Joe giving a little playful sass, joking that he's kinda got a feeling she's just here for his wallet. 'How could you love me if you don't get any money out of it huh?' But I'm not certain. That's my best analysis of it.
I hope this was helpful! I'm gonna tweet the band and see if I was close. I LOVE this song and hope you do too :)