Start with the part most travel sites will not tell you: there is not much to book here, and that is fine. Grand Rapids has perhaps two dozen bookable guided experiences at any given moment, most of them priced around forty dollars, and the large majority of them involve beer. Compare that to a coastal town of the same size with a hundred and fifty boat trips on sale and you can see the shape of the place. This is a city you walk, drive and drink your way around under your own direction. A guide is not the default here; it is a tool you use for one specific job.
The job it does best is the beer. Roughly thirty-five breweries trade inside the city limits, spread across three or four separate districts, and the arithmetic of visiting them properly is the arithmetic of not driving. A brewery tour buys you a driver, a route somebody has already sequenced, and usually a back-of-house look you would not get on your own. For two people who want to spend an afternoon tasting rather than navigating, it is the single best value booking in this city, and it is the only category where the inventory is genuinely competitive.
Food tours are the second real category, and they work here for an unusual reason: the good eating sits a mile or two from the hotels, on Wealthy Street, in East Hills and along Bridge Street. A walking food tour solves the orientation problem as much as the eating one. You come out of it knowing where to go back to on your own for dinner.
After those two, the honest advice is to stop booking. The downtown attractions do not need a guide, the architecture is best seen with a map and an afternoon, and the one thing that would obviously suit a boat — the Grand River through the middle of town — is currently a construction site while the rapids are put back in, which has taken the entire water category off the table for the duration.
There is one more thing a thin market changes, and it is worth absorbing before you open a booking site. In a destination with two hundred operators, a bad choice costs you an afternoon. In a destination with twenty, a bad choice may be the only choice, and the tour that runs on the Saturday you are here is not necessarily the tour you would have picked. So the sequence matters: decide which single experience you actually want a guide for, check what is running on your dates, and build the rest of the trip around that fixed point rather than the other way round. That is the opposite of how most people plan a city break, and it is the right way to plan this one.
What follows is what exists, what it costs in the bands we have actually observed, what it buys you, and where the same day is better done yourself for nothing. Where this page says a tour is not worth it, that is not modesty. It is the recommendation.