What is a good search app for website with 70k products?

[yoonlaser]

I've been looking for a search app that can show appropriate search results.
We have more than 70k products and monthly search operations are about 10-11k.
Search apps for this size are very expensive, so I wonder if you can recommend any affordable and versatile search apps.
So far we've tried Rapid search, Algolia and some others.
Which app is going well on our site?

[StephensWorld]

Would be helpful to know what features you need the search app to have, as well as what limitations/problems you have with the regular search functionality that's built into all premium themes.

[yoonlaser]

Currently if i search for 'camera' then the search result shows camera lens, camera bags, tripods, etc.
So the first real camera comes up at the end of the first page.
I need the demote feature so we can demote products under certain categories something like video accessories, camera accessories. 
If the search engine has a setting to demote any products tagged with 'xxx accessories' then we can put the accessories to the back of the search result. I don't want to exclude those products, though just want to put them behind.
My theme is 'Enterprise' and I'm currently on the Shopify advanced plan.

Thank you!

[StephensWorld]

The enterprise theme actually has a built-in functionality for "product type dropdowns" which you could use to help filter which results are shown. See here for how to set it up: https://support.cleancanvas.co.uk/hc/en-us/articles/11128831722013-Search-bar 

[yoonlaser]

Thank you for your answer.
First 2 are too expensive for us. Let me try the other 2. Thank you!