Hi,
Try changing the line:
'<input class="slider_input slider_input_start" id="slider_'.$filter->filter_namekey.'_'.$divName.'_start" value="'.$minVal.'"/>'.
to:
'<input type="number" step="0.01" class="slider_input slider_input_start" id="slider_'.$filter->filter_namekey.'_'.$divName.'_start" value="'.$minVal.'"/>'.
and the line:
'<input class="slider_input slider_input_end" id="slider_'.$filter->filter_namekey.'_'.$divName.'_end" value="'.$maxVal.'"/>'.
to:
'<input type="number" step="0.01" class="slider_input slider_input_end" id="slider_'.$filter->filter_namekey.'_'.$divName.'_end" value="'.$maxVal.'"/>'.
in the file administrator/components/com_hikashop/classes/filter.php
That should help.
Please let us know how it goes. If it works fine, we'll include the change on our end for the next version of HikaShop.