I have used ebay for 5 + years. I have had outstanding luck on both selling and buying. It has gotten a bit harder to find a reasonable purchasing pricing compared to just a year ago. Seems like everyone starts out at retail or a great many are not bothered by the higher prices and just like to win auctions no matter the cost. A seller has it a little harder and pays the cost of the ebay fees. I will say I have heard stories of bad actors buying an item and then falsely claiming that seller not living up to the listing or not shipping etc. The complaint then stops the paypal deposit from being transferred on the fast track and/or until the conflict is resolved. Complaints can really kill the sellers ratings that hurt the ability to sell again. I have not had a problem..... knock on wood.
I make sure to be very descriptive, plenty of pictures and always try to pack with great care so that it shows that I cared about the buyer purchasing from me and the kits safe arrival. I communicate with the seller as much as possible so they again know I care about the purchase and it's safe transfer of ownership. The "treat others as you want to be treated"" ideology has worked very well for me in all of my online sales and purchasing activities.
With selling prices going up on ebay, if you are thinning the stash you would probably make out good. The fees on the plastic kits are not too bad considering the number of people who will look at your listings. I am always looking at listings in the plastic kit area and the ones that get my attention first are "Auction" listings with a starting price way less than list price. You can help control your loss with the "reserve" settings. One needs to be aware that one can quickly add up fees $$$ in the listing costs with the different ad options for making the ad "pop". Their is a happy balance between your ad fees and the selling price. I look at how high your fees add up - what reserve fee is, fees for big bold lines of the listing title lines, extra picture fees etc. all added the listing base charge vs the value of the item being listed. I have found I can usually balance all of this to be happy with the sale of my goods. It seems to me it's all about balance.
I also want to add that some of the seller tools have helped in making the fees a little more palatable.
The shipping calculators and the shipping label system works very well and makes shipping nearly painless for me at least.
I do wish ebay were free but it is what it is. It is a lot of fun to watch and hunt for kits I want to add to my stash. I have growled at the screen when I lost a rare kit over missing it by .20 cents but I've also cheered when i picked up a real bargain. Well sorry if I was a bit long winded, but hope it helps a little in your stash management.
All the Best!
Bill
PS
I wondered if you are located in Mississippi as your screen name suggests? I am in NE Mississippi (Iuka, MS) and am hopeful that you might know if there are any active model clubs in my area.
Thanks
Bill