fair pricing

could somebody plaese help a newby,I dropped a quote off the other day quoted $308.64 for 12 t-shirts 12 hoodies simple two color spot design both sides thought price was fair good profit built in (wife has everything figured to the tenth of a cent) customer showed quotes from four other printers rangeing from 736 to 957.oo question is , is it commom to charge for flashing between coats of white or to charge for double coat of white on dark shirt there was even an extra charge for black ink on light shirt. Now this being asked these other companies main income is collage athletics they onlydo locall merchants as a filler where business logos are my bread and butter . Could somebody plaese explain pricing structure to me?