I have money to spend on marketing but no idea where to put it - help me go from $2K to $10K MRR

I'm a solo founder with a consumer subscription app doing ~$2K MRR. About 3,000 active users, 130 paying subscribers. Growing organically and ranking well in the App Store.

My only paid channel right now is Apple Search Ads which is working decent but cap and spending more not help. I have budget I'm ready to invest but I don't where.

Here's what I'm struggling with:

Social media consistency - I'm one person building the product AND doing marketing. I post when I can but it's not consistent. Looking for an all-in-one AI tool that can handle content creation (including video) + scheduling + posting across platforms semi-automatically. I've seen Narrato, SocialBee, Buffer mentioned a lot. What are people actually using and getting results from?

Growth help - I reached out to a few app marketing agencies and they want £25-30K/month retainers. That's insane for my stage. Has anyone had good results with freelance specialists or smaller, scrappier agencies that work with early-stage subscription apps?

I'm not looking for generic advice like "just run Facebook ads." I want to hear what actually moved the needle for people who've been in this $2K-$10K MRR gap with a consumer subscription app.

What would you spend on first?