Software engineering to Investment banking

I am currently working in the market research industry and have 2 years of experience under the title of "Analyst". I genuinely want to work in the finance industry in the front end division of the big 4. I know it requires an MBA or any finance major degree to be eligible to work as an investment banker in these firms but I cannot afford an MBA at the moment so I was planning to get into one of these firms at an engineering position and then down the line switch into a front end role at that same firm with the help of a sponsored MBA or something related to that. Does any of the big 4 sponsor an MBA to a person to offer career growth from one division to another in the way I am planning to do so?