You'll be hard pressed to find a school that does IR raining in an aircraft for 100$ unless they are using IR certified C150/152 , most schools on the cheaper side tend to use C172 or PA28s for around 120$ an hour and 50$ for instruction. If the latter is something you can stretch your budget too then contact Florida Flyers in St Augustine , otherwise you'll need to find a school or independent instructor that uses IR C150/152 to stay within the rate you specified above.