Search Plus has two tiers - Free and Pro.

You can try out Search Plus with no commitment today and upgrade to Pro if you need later.

There are a few differences between the tiers, which mostly come down to the scale of the project you're using Search Plus with.

Free Pro
Price Always Free $99 (once per site)
Built for.. Simpler and smaller content sites. Charities, hobby projects, micro builds... Mid to large site builds. Sites that are more content heavy, or with more custom setups.
Maximum Indexes 3 Unlimited
Maximum Items Per Index 250 Unlimited
Regular Support
Premium Support
Priority Feature Requests
Helping ongoing development