what do you mean. i still don't get it. what are 5 big instagram accounts ?
Accounts with lots of followers.
Like..
instagram.com/justinbieber
instagram.com/selenagomez
instagram.com/instagram
instagram.com/sexualising
instagram.com/okdayum
That's too far fetched. Selena Gomez has 91M followers on IG. Those people that you just mentioned are on top of the list of the most followed accounts on IG. I don't think Justin Bieber would do stuffs like that for 2$. If I ever had an account that has millions of followers, one promotion would get me thousands of dollars.
You want a promotion from an account that has millions of followers and you want 5 of them for 2$? Funny.
No, what OP wants is a comment advertisement, where you post a comment on a photo on one of these big pages in order to promote OP's site. He doesn't want a shoutout from a celebrity; chances are the celebrity wouldn't give the shoutout to him even if he paid a lot of money.
It's an easy and reasonable task for people to do for $2, however OP has not been paying people so you might want to wait until he sends the first payment before you carry out this task.