Ads vs links or Bots for ASO

Hi, i have one app in position 30 for 4 keywords

1) I have one oportunity to buy a review on a android blog for $30 with 1 link to my app, i dont know how many installs i can receive
2) I can spend 60 usd on 4 keywords geting installs by keyword for 5 days
3) i can spend 60 on facebook ads for installs (i think i can get 1k of downloads for this budget or more)

In your opinion wich option can give the best roi?

Ads, fb or adwords

You don't say how many downloads you can get in the second option (adwords?).

Just based on what you've written I'd say the third option gives you the best ROI.

Buying the link will probably not get you 1000 downloads me thinks.

the second option isn't adwords., its a bot