If you can find my journey thread on here you will see that I grew 1.5k followers on the first day then shot from 5k to 50k in a few weeks. I didnt spend more than $40 to get to that point and half of that was testing different shoutout accounts. I will say though that I only know of this working in my own niche but I dont see why it wouldnt for yours. To get to 50k i bought likes off big accounts. Likes are the most underrated part of instagram, i can like someones picture on my own account and get them 500-2k followers in 24 hours whereas a 1 hour shout out wont get anywhere near them numbers. The best thing about this is that shout out sellers never get asked to sell them likes so with a bit of persuasion you can get a like for dirt cheap, I managed to get 7 days for $10, I got 15k+ followers in that same week. Make sure to get them to like your most recent photo for it to be most effective. This will help you get out of that slow growth stage and once you get up to around 50k with this method your account will grow fast organically.