I would expect the following code to start my slider at '30' in it's range of 0-250, but yet it is not.
$(function() {
$( "#slider" ).slider({
value: 30,
min: 0,
max: 250,
step: 1,
slide: function(event, ui){
$("#edit-varprice").val(ui.value + ".00");
}
});
});
Its working fine for me. See jsFiddle Demo.
Perhaps you are missing something else or doing something in other parts of your code, can you post full code?