Well, it depends on what you really want - awesome new sounds or a board for your babies to live on.
What kind of music do you play?
The Xero seems like the all-around multi-tool of pedals. I have no experience with one, but from what I understand of the (very knowledgable and smart) users here it is a sure win.
I own the FrantaBit and can assure you it is unconventional. Especially with an expression pedal and some delay. It is plain insane.
I'll bet you could get a less expensive board, maybe a pedaltrain, and a pedal and meet your $300 mark. And I'll bet there will be more thought out answers to come

. The IE pedals will not let you down. Best of luck!