Garden centre shelves stock a dozen different sprays that all do roughly the same job, priced anywhere from under twenty dollars to over seventy, and the label rarely makes clear why. Most of the difference isn't effectiveness, it's branding, pack size and whether the active ingredient is generic or dressed up as a specialty product. Knowing the real prices side by side makes it much easier to spot when you're paying for marketing.
Most of the difference isn't effectiveness, it's branding, pack size and whether the active ingredient is generic or dressed up as a specialty product.
At the cheaper end, a Kiwicare pyrethrum-based ready-to-use spray typically runs from around seventeen dollars, and Yates Pyrethrum sits in a roughly thirty-two to forty dollar range depending on pack size and concentrate versus ready-to-use format. Pyrethrum, made from chrysanthemum extract, is a genuinely broad-spectrum contact insecticide with decades of use behind it, and paying at the lower end of that range for a plain pyrethrum product buys the same active ingredient as many pricier "specialty" pest sprays.
Yates Mavrik, a synthetic pyrethroid, typically sits around twenty-six dollars and is aimed more specifically at harder-to-kill pests than plain pyrethrum handles well, which is a genuine difference in the active ingredient rather than just branding.
Neem-based products show the widest spread of anything on the shelf. Grosafe BioNeem typically runs around thirty-three dollars, while OCP Eco-Neem, a different formulation and concentration, can run as high as seventy dollars for a comparable pack. Both are genuinely neem, and neem's real strengths and limits are covered in detail in this site's dedicated article on the evidence behind it, but the price gap between two products with the same core active ingredient is exactly the kind of thing worth checking before buying the more expensive one out of habit.
None of this is an argument for always buying the cheapest bottle on the shelf. A synthetic pyrethroid and a plain pyrethrum are not interchangeable for every pest, and neem's slower, gentler action is a genuine trade-off against a faster-acting contact spray, not simply an inferior version of one. The point is narrower: once you know what active ingredient you actually need for the pest in front of you, from the site's specific pest guides or the psyllid and neem articles here, comparing products on that basis rather than on which one has the scariest bug on the label is the difference between a nineteen-dollar bottle and a seventy-dollar one doing the same job in your garden.
Over a full growing season, spread across tomatoes, brassicas and whatever else needs a spray at some point, that gap between the generic and the dressed-up version of the same active ingredient adds up to real money, often the cost of a whole extra season's worth of seedlings for no extra control.