BiTel

# mysql -uroot -p -e "select count(*) from bgbilling.tariff_plan;"
+----------+
| count(*) |
+----------+
|      650 |
+----------+

SELECT
   p.id AS tariffId,
   p.title AS tariffTitle,
   MAX(CONVERT(IF(LOCATE('type', n.data) < LOCATE('%', n.data), SUBSTRING(n.data FROM LOCATE('%', n.data) +  6), SUBSTRING(n.data, 6, LOCATE('%', n.data) - 6)), DECIMAL(10,2))) AS tariffCost
FROM
   bgbilling.tariff_plan p
   LEFT JOIN bgbilling.module_tariff_tree t ON p.tree_id = t.tree_id AND t.mid = 2
   LEFT JOIN bgbilling.mtree_node n ON n.mtree_id = t.id AND n.type = 'month_cost'
GROUP BY
   p.id;