The technology-mad teen already earned more than £40,000 by creating his own video game and a financial app for the stock market after teaching himself how to code.
He claims the price comparison site is unrivaled by competitors and can become a 'household name'
The sixth-form student said: "We met the investors in London, they were a global data driven company, and they didn't realise I created all the technology involved.
"The offer was rejected in December, just before Christmas.
"The main reason we rejected the offer was because, if the technology and concept is worth millions already, just think how much it will be worth once people use it.
"I understand this is a big risk for me but I want to create this as a household name, and at the same time make something for myself.
"The big thing about what we're doing is that there are no competitors - this is a real-time money saving expert - it's like a Bloomberg for the general public."
Set to be launched on January 28, the young entrepreneur said he now hopes to inspire other teens to get involved in the business world.
The business-savvy teen previously hit the headlines when he created Project 2006, a video game which had a £5.99 per month subscription cost and made £30,000, as a 12-year-old.
Ali, who still lives with his parents and siblings, became interested in computers from a young age and taught himself how to code by watching YouTube videos and reading books.
The teenager said: "Right now I work from the bedroom day and night but we're launching this globally so we will need to travel more.
"My mum used to hate me going on the computer all the time but I think she's proud of what I'm doing now and my brother has been inspired by what I'm doing.
"I have learned everything from watching videos and books - there's not much being done in schools and the education system is a bit messed up.
"Anyone can revise for exams but I don't think enough is being done to prepare people for getting out in the real world.
"I want other people to be inspired and I want to inspire young people to develop a work ethic - it disgusts me when you see young people just getting drunk on a Friday night."
Ali, who estimates that he has earned around £41,000 from his businesses, said: "If I see some clothes or trainers I like I'll buy them but most of my money is saved.
"I look at the things I make as inventions and I like to be proud of building them up.