Short answer: the best places are (1) the major carriers (Verizon, AT&T, T‑Mobile) when you can use trade‑in + new‑line or plan credits, (2) the phone/watch manufacturers’ own stores (Apple, Samsung, Google) for trade‑in promos and direct discounts, (3) big retailers (Best Buy, Amazon, Costco, B&H) for instant price cuts, gift cards, or member-only bundles, and (4) certified‑refurbished / marketplace options (Apple Certified Refurbished, Amazon Renewed, Swappa, Gazelle) if you want much lower prices with reasonable warranty. Below I give where to check, what each option is good for, and a short checklist to maximize savings.

Where to check (and why)

• Carriers (Verizon, AT&T, T‑Mobile): carriers frequently offer the deepest headline discounts on brand‑new flagship phones and watches when you trade in an eligible device and activate a line or select a qualifying plan — offers in Oct‑2025 include up to roughly $1,000–$1,100 off new iPhones and big credits on Samsung/Pixel when you trade in. If you plan to keep service with the carrier anyway, trade‑in credits + installment promos are often the best way to make a new flagship nearly free. (tomsguide.com)
• Manufacturer stores (Apple, Samsung, Google): buying direct often gives you guaranteed trade‑in credit, exclusive storage/color options, limited‑time promotion bundles (e.g., free earbuds, storage upgrades, or service credits), and more predictable reclaimed value for old devices. Apple’s Certified Refurbished store also sells returned/like‑new devices with a warranty and savings (Apple lists “up to ~15%” savings for refurbished iPhones). Samsung’s site currently lists trade‑in credits and site‑exclusive offers on Galaxy phones and watches. (Apple.com)
• Big retailers (Best Buy, Amazon, Costco, B&H): Best Buy and Amazon often run instant discounts, gift‑card bundles, and retailer‑specific trade‑in/activation deals (Best Buy has frequent $100–$400 off unlocked or activated models). Warehouse clubs like Costco add member bundles, occasional gift‑card or accessory bundles, and extended return/installation advantages for members (Costco runs notable holiday/Black Friday electronics deals). These retailers can beat manufacturer pricing on unlocked units or offer better short‑term discounts. (laptopmag.com)
• Certified refurbished / used marketplaces (Apple Certified Refurbished, Amazon Renewed, Swappa, Gazelle, Decluttr): if you want a substantial discount and still reasonable warranty/return options, certified refurbished or lightly used devices are the best value — Apple Certified Refurbished includes a 1‑year warranty and can be significantly cheaper than new. Amazon Renewed and reputable marketplaces let you save more but check warranty/return terms. (Apple.com)

Which option is best depending on your priorities

• Lowest possible price on brand‑new flagship and you don’t mind a carrier plan: carriers + trade‑in (Verizon/AT&T/T‑Mobile) typically win. (tomsguide.com)
• Best combination of convenience + predictable warranty for Apple Watch / Apple iPhone: Apple Store / Apple Certified Refurbished. (Apple.com)
• Best unlocked phone discounts without a carrier swap: Best Buy or Amazon (instant merchant discounts, gift cards). (laptopmag.com)
• Best value without buying new: Apple Certified Refurbished, Amazon Renewed, Swappa. (Apple.com)
• Best for bundled savings (phone + watch/accessories): look at carrier bundles and Samsung/Apple direct promotions (they sometimes include free watches, earbuds, or storage upgrades). (Samsung.com)

Simple 6‑step checklist to maximize your discount

1. Compare trade‑in value first. Get an estimate from Apple, Samsung, and your carrier — carrier credits are often largest but usually require activation and a multi‑month payment plan. (If you’re upgrading anyway, carrier trade‑in can be the biggest single saving.) (Verizon.com)
2. Check manufacturer promotions. Samsung and Google often have site‑only offers (instant discounts, free storage upgrades, or freebies) that are stackable with trade‑ins. (Samsung.com)
3. Check big retailers (Best Buy, Amazon, Costco) for instant discounts, gift cards, or member bundles — retailers sometimes beat manufacturer pricing on unlocked units. (laptopmag.com)
4. Look at certified refurbished if you’re comfortable with non‑new hardware — Apple Certified Refurbished is a safe place for Apple gear. (Apple.com)
5. Stack savings: use credit‑card purchase promos, promo codes, student/military discounts (if eligible), and carrier‑specific referral or port‑in credits. Also check manufacturer upgrade programs that give trade‑in credit spread across monthly payments. (tomsguide.com)
6. Time your purchase: major sale windows (Black Friday / Cyber Monday, manufacturer “Week” promos, new‑phone launch periods) commonly have the best instant deals or bundles — check retailer/brand pages as those dates approach. (Costco and other retailers post early Black Friday ads and member offers.) (timesunion.com)

Quick comparison examples (typical, Oct 2025 market)

• If you want the newest flagship iPhone and want lowest out‑of‑pocket: carrier trade‑in + new line (AT&T/Verizon/T‑Mobile have up to ~$1,000–$1,100 credits with qualifying trade ins/plans). (tomsguide.com)
• If you want the newest Samsung phone/watch: check Samsung.com for trade‑in credits + site promos (Samsung regularly offers up to several hundred dollars in trade‑in credit and storage upgrades) and compare to Best Buy/Amazon for unlocked discounts. (Samsung.com)
• If you want a discounted Apple Watch: Apple Certified Refurbished or carrier promos (sometimes included free or discounted with phone deals) and warehouse clubs (Costco) during holiday promotions are good bets. (Apple.com)

If you want, I can:

• Look up current live deals for a specific phone + watch model you have in mind (I’ll compare carrier trade‑in offers, Samsung/Apple/Google direct promos, Best Buy/Amazon/Costco prices and refurbished options), or
• Give step‑by‑step help valuing your current device for trade‑in and picking the single best offer.

Which phone and watch models are you looking for? (If you want me to pull live offers now I’ll compare current prices and cite the exact promos.)