It’s a monthly budget ? If yes do M/S method to your main account and sell your course with social proof I am sure you will be rich haha
If it’s your total budget, I’d try the method with less account, even if you can’t sell your training much you’ll have lots of followers and that is really valuable for you future.
I’ve see a lot of accounts in the fitness niche do this with stories and highlights. Make the first highlight on your page nothing but successful before and after a and social proof from real customers or your friends sending you take texts or dms. Social proof is huge. If you can make a reel of success stories from past customers that would be a great video for igtv and you can even post that on your feed. For that low of a budget I’d suggest working with a fiverr social media strategist who can make some baller graphics for you and give you a game plan from which you can launch from.