Cheaper isn't automatically worse, but it's worth understanding why it's cheaper before you sign. The most common reasons a quote is lower are a generic or lesser-known inverter and panel brand instead of an established name, fewer panels, a string inverter instead of a hybrid, or a more basic install (no battery, simpler roof). None of those are necessarily bad — they might be exactly right for you — but you want it to be a deliberate trade-off, not a hidden downgrade.
Be wary of unknown generic kit quoted purely on price. The concern isn't always the day-one performance; it's long-term support, warranty backing, and whether the components are essentially knock-offs of better-known brands. A robust, well-supported inverter from a mainstream manufacturer can be worth a modest premium for the easier expansion and aftercare. So when comparing, line the cheap quote up against the others spec-for-spec and see what's actually different.
Equally important is who's behind the install. Watch for outsourced/subcontracted work where the company you pay isn't the company doing the job — that's where poor quality, hard-to-reach aftercare, and finger-pointing when something goes wrong tend to show up. Check reviews, ask whether they use their own crews, and confirm what happens if you need them back. A keen price from a reputable installer using good kit is great; a keen price that turns out to be a lottery on subcontractors and no-name components is a false economy.