Old school knottie here, saw your post re:Mariachis. For my wedding I wanted to book a Mariachi too but the more research I did the more I found out how expensive they were that's when I found the alternative which is a Trio. I booked Los Consentidos & they were awesome. It's softer more romantic music, which I found more appropriate for the situation. Their prices were so reasonable I was able to book them for a longer block than I would have booked the Mariachi for. Everyone loved them & I really couldn't say more, they were amazing. Here is their site:
http://www.myspace.com/losconsentidosmusic