Couple years ago I trained a horse who never started til his 5 yo year - he was a big, big boy and they didnt start him til late. We got him running around April,and he made about $25k running 2nds and thirds running MSW for a $24k purse but did not break his maiden. Owner lived in Florida, horse needed a break after running his guts out many races in a row, so he returned home in early November for some R & R. Based on his past performances he was a solid MSW contender on turf that needed a few months off. However, he DID NEED about 4-6 months of layup time, which lowered his value to about 15k, which also took into consideration his soundness. Over the winter he would turn 6 and be ineligible to run in Florida. But he was a 6 yo maiden who was worth $15k, eyes closed. It happens.
In every state there are different rules for maidens, most owners and trainers are or should be aware of the rules that are in effect for states they race in or buy horses from (such as buying from Florida for this exact reason).