I have a friend who is a power seller, but she deals in resale items she gets at goodwill for like a dime and she opens all her auctions at .99 with no reserve. She makes some decent pocket money.
I, however, am doing Etsy, because I make the stuff, it's lower-cost to list, and I can set my prices accordingly.
The trick with eBay is you really have to be aware of the overhead. If you are doing a lot of small stuff, or one BIG ticket item, you can usually make your money back. But you have to pay attention when you're creating your listing--bold font? Surcharge. Highlight Listing? Surcharge. Insertion fees are graduated based on starting price. Reserve and Buy It Now options? Fees. Also, remember that while a reserve protects you, it can annoy a LOT of people. If you set the reserve at $500, but open the auction at 9.99 to avoid the next upcharge for listing, you are just going to REALLY annoy bidders who try to guess their way to your reserve price.
It's not THAT time consuming, it's mostly just a matter of paying attention and planning your listings, and remembering that there IS overhead.
A friend of mine made a good living based solely on ebay several years ago. He had a niche market though (non-horsey), and was also a programming/IT whiz. Everything he did online was automated, and he never laid a finger on most of the products but had them shipped directly from source. All it in all, it was still a full-time job for one person, but the way he was set up made it possible to do a significant amount of business. Family circumstance forced him to give that up and take on a job with a benefits, but he did very, very well.
What about the people who sell resale items like for ex. Rambo blankets. They must somehow make some money or why do it? Right? Although, when I've looked on ebay for Rambo or Rhino blankets, they price is the same as other online companies.
I sell a small quantity of vintage furniture and home accessories on eBay and Etsy. Like danceronice, I find Etsy easier to deal with, but when I just want to clearance things I use eBay since the items get more exposure.
Since I sell a lot of breakable items, the packing process is what takes the most time for me and is the most aggravating. I get free boxes and packing materials, mostly recycled from my own online purchases and a furniture store that I work with. Otherwise you have to factor in the cost of boxes and bubble wrap, which can really add up on inexpensive items! The fees on eBay will also get you on the lower priced items - you can end up making very little profit once you take out the eBay and PayPal fees, your packing materials and the time spent creating the ad and getting the sold item to the post office or UPS!
I make a little bit of money doing this, but it is mostly for fun. I go to garage and estate sales when I have time and find things I think are cool, do basic repairs if they need it, and then try and sell them. I do this in addition to a "real" job, so luckily I don't depend on it to pay the bills, otherwise not many of them would be paid at the end of the month!
Because they likely aren't reselling rambo blankets they are probably authorized dealers. I used to own a mobile tack store, had an online store as well as an eBay store. EBay is just not worth it. It's a giant pain.
If you're selling used horse stuff on ebay, it better be clean, and do not expect to get anywhere near retail for it unless it is in fact new.
If it's something on the rare side and in good condition, or in a popular or uncommon size in good condition (see a pattern?) ebay may be the way to go because it IS still the most popular auction site, and it does allow buyers to compete and raise the price.
I do not expect to make a huge profit dealing on ebay. I will use it for things I can't put on etsy (for those unfamiliar, etsy items have to be handcrafted or vintage, ie at least twenty years old.) I will use it for certain types of collectibles. And, ironically, I use it to buy watch parts I need for my jewelrymaking. I did get my saddle off ebay as well--I needed a PDN, and I wanted it cheap. That's another thing, people do NOT go on ebay looking to pay full retail.
I sold a few tack items on eBay some years ago, and got back on to sell a few things this year. Some observations:
-People don't seem willing to spend nearly as much money on horse-related stuff now, compared to a few years ago. I sold a couple saddles that I bought on eBay for a fraction of what I paid for them a couple years ago, and a lot of stuff didn't even get a bid at super low listing prices. Everything I listed was either new and had been in storage or was very lightly used and cleaned, photographed well, etc. When nobody bites at 10-25% of the what I paid for it...ouch.
-Fees have gone up, both eBay and PayPal, to a pretty staggering percentage of total sales. Especially painful is paying listing fees for things that don't sell. A little here and there adds up.
-The service is a PITA to use and friendly to neither seller nor buyer. Some items I had to re-enter the information several times after it all went "poof" with no warning. And the feedback system still sucks, since everyone holds everyone else hostage (been on both sides of that fence: Seller took money from a bunch of people and disappeared, eBay said "oh, well. Too bad." Buyer changed her mind after winning an auction and backed out. I had to pay the eBay fees for her win, and more fees to relist and sell the item at a much lower winning bid.)
IMOHO, if you could come up with a good, equine-based alternative to eBay, you could have a lot of business. The websites I found for selling tack were either tiny niche markets or so under-subscribed as to be a waste of time even posting items. Craigslist ended up being the best, and it's clearly not set up terribly well for selling tack.
I used to sell collectibles (Secondary Market) for Dept 56 stuff. I sold quite a lot on EBAY several years ago. But they kept on changing the fee structures and it finally came to the point it just wasn't worth it.
Last year was my last purchase and sale on EBAY although hubby buys football jerseys on occasion.
Packing product was my biggest hurdle. The packing materials can get pricey if you aren't careful in managing costs.