My dad has pretty much stopped me from using ebay after i got the wrong product for the second time. Is there any alternatives to finding interesting bulbs besides websites where i might get the wrong product i ordered? Is trading with other collectors a good strategy for getting lamps that you cant just outright buy from a store? Any other tips? Thanks for the info!

Also i don't know where to put this so mods you can move this around to where you see fit.

I know of mercado libre as a website where you can source lighting from Latin America if you can understand or translate the Spanish or Portuguese on this website.

I'd agree trades with others are the safest bet, or in-person pickups.  If it's an eBay seller with only one of the particular items, it's not too likely they'd send you the wrong item either.  If they have lots, sometimes they'll make a mistake or substitution.  The same can happen with a lighting retailer, particularly with an oddball lamp or one that's no longer in production.  Fortunately at least in my experience many eBay sellers are willing to make a prompt refund if the error was their fault, and frequently they'll offer a refund without requiring that the item be shipped back.  However, every seller has their own policy and procedures.  Some are not as willing to admit blame, or might be hesitant if they suspect fraud.

I have a few alternatives. I rarely use eBay to buy lighting stuff due to the high shipping rates as most sellers are based in the United States. Unfortunately most of my alternatives are less convenient than eBay as more are more your mileage may vary.   

Local resale sites
These would be the online classified sites such as Craigslist, Kijiji, Facebook Marketplace where you meet the seller in person to pay and pick up. Technically not local but hobby related buy and sell groups on Facebook and forums are also good.

Surplus stores
Ssearch your local area to see if you can any industrial surplus dealers that will sell to the public, electronic surplus dealers are also good for finding odd items too. Any building material salvage dealers might also be a good source.

Habitat for Humanity Restore 
I think most of us in the US and Canada already heard of them. They're basically a building material oriented thrift store and sometimes some rather odd items show up on their shelves. Some areas might also have some similar stores operating independently.

Thrift stores
Value Village/Savers, Goodwill, Salvation Army or independents. Sometimes interesting lighting might show up there but from my experience finding anything lighting related not normally used in the home is rare though.

Flea markets 
In my area these seem to be quite hit or miss and mostly miss for finding vintage lighting but I guess you'll never know.

Independent hardware stores
These would be places like ACE, Home Hardware, Tru Value, as well as any unaffiliated locations. Generally the older looking the better chance you have, hit or miss but sometimes you'll come across some good NOS stuff that's been sitting on the shelves for years.

Electrical/Lighting supply houses
Most are good if you're looking for modern in production stuff but for the old stuff you have a higher chance of finding them if you go a older/more established branch. 

Antique stores and markets
Depends on the store and what demographic they cater to. Ones that sell a lot of "man cave" related items tend to sometimes have things like lamps and streetlights. Prices may vary from cheap to reasonable to overpriced.

Vintage lighting and architectural antique dealers
You might find some rather unique fixtures there but prices tend to be way more upscale than the other options.

There are some thrift store that have out building for building material kinda like restore.  Rual area junk shop works out well
  Ive once got bunch of reflector mercury lamps from a old bank
   That about to be raze over. I just get my lamp changing poles
  Just help my self.  I even done the same with city nema buckets.   To preserve some nema HPS nema buckets in San Antonio just replace cycling HPS lamps since they spot replace them for leds.   So I just relamp them my self on my old child hood streets.

Here in the UK we have Gumtree as an alternative. 
We haven't looked for lamps on there though.

Here in the UK we have Gumtree as an alternative. 
We haven't looked for lamps on there though.

You can also get Australian lighting off of gumtree as well.