What do you mean, built for large sites? Ahrefs, SEMRush, Moz, Majestic, Mangools, Screaming Frog, Yoast, SEO Framework, and Keywords Everywhere are all non-enterprise focused and are geared towards small businesses just as much as (if not more so than) large websites.
Of the above, Mangools SEO tools are the most affordable of the full SEO toolsets. And from what I can tell, Mangools gets the job done just fine.
I also love Keywords Everywhere, which is both a cheap and a pay-as-you-go way to pull volume #s straight from Google.