CREATE TABLE table_15239 ("Company" CLOB, "Plan name" CLOB, "Technology" CLOB, "Maximum download speed/ kbps" CLOB, "Data limit/ GB" CLOB, "Monthly price incl. VAT/ CZK" CLOB)

What plan has monthly prices of 300, 500, 750, 1000?
SELECT "Plan name" FROM table_15239 WHERE "Monthly price incl. VAT/ CZK" = '300, 500, 750, 1000'
SELECT "Plan name" FROM "table_15239" WHERE "Monthly price incl. VAT/ CZK" = '300, 500, 750, 1000'