Thank you for your answer. I fear from that. Yesterday I tried search solution, and found the SQL Query string comparison is working with alphabetic order. (https://stackoverflow.com/questions/26080187/sql-string-comparison-greater-than-and-less-than-operators). But I don’t know, what happend with the value, when I select in AjaxSearch Pro Custom field filter to text and select one numeric operator. The plugin make any conversion in text value?
(I tried change custom field type to text, but it wouldn’t work same.)