I understand the feeling of not being able to negotiate because 95% of my purchases are small ticket items from national chains, but if you think negotiating is dead then you aren't looking.
I am NOT a strong negotiator, I'll usually only ask if I'm buying a few things or my checkout price will be greater than ~$200, but just asking will usually be enough. "Can I get a discount" or "can you throw in some of this stuff for free." But even with that, I've been able to get plenty of discounts.
And that expands a TON if you add floor model/open box/dent and ding items. Almost any store will give you a minimum of 10% off on AT LEAST those items.
Places you can negotiate:
* Any car dealership
* Buying houses or real estate
* Renting apartments/houses not managed by multi-city corporations
* Music stores, excluding Guitar Center
* Guitar Center (somewhat)
* Mattress stores
* Furniture stores (that are at least on the level of Ashley furniture) or independent (so no Ikea).
* SaaSes that have sales teams [email them and ask, they often will give discounts if you have a better reason than "I want a discount" which is a pretty low bar. Like student (real student, not I still have my college address 10 years later), military, I'm a poor startup founder and can't afford the full price. <- I've used this a few times pre-revenue]
* Smaller software companies that aren't selling games (email them and ask, they often will give discounts if you have a better reason than "I want a discount" which is a pretty low bar)
* ANY place that sells anything used from slightly used to antiques
* Farmer's markets
* Boutique food stores (this one is kinda iffy unless spending a fair bit)
* Flea markets
* Dentist offices (the approach is different here usually appealing to loyalty discounts, personal hardships, or extra cosmetic type services)
* Mall kiosk vendors oftentimes
* Outside of the US any kind of vendor in a shop that is in a specialized mall (ex. In Seoul in the electronics district, there are malls full of small vendors that have similar inventory as everyone else, you can haggle a ton)
* Any independently owned shop that has most items retailing for >~$50 or average ticket price >~$100.
* Non-chain Restaurants (but I'd generally avoid it unless going high end because margins are usually tiny)
* Pretty much ANY store that hasn't "standardized" itself to death.
* Rental cars
* I could keep going.
Places you can't:
* National chains where the sales staff is minimum wage. Walmart, Best Buy, Target
* Stores selling small-ticket items (average purchase is under $100)
* Online retailers (outside of standard coupons, etc)
* Grocery stores
* Regional/nationally managed rentals.
* I'm having trouble thinking of other places you can't negotiate at least a little at...