Am I able to report them to EBay?
Yes, and if they do this repeatedly then they might lose buying power; also you can ban buyers who have done it repeatedly from doing it to your sales.
As a buyer, I am able to choose when I want to bid on an item, and a lot of my decision will be based on the buyer's feedback score . However, as a seller, I seem to have no choice on who is meant to buy my item.
I think opposite is true, unless you keep a list of annoying sellers, it's harder as a buyer to avoid the specific sellers who upset you in past; there are no tools except your own memory & record keeping to help you. You have to hand search that feedback to see what a seller did to annoy people. Whereas as a seller, you can automatically screen out bidders who have history of not paying. Anyway, most people don't leave any feedback.
will probably get less than what they were going to pay for it.
Then that lower price is the real max price you were ever going to get anyway, it's not an actual loss you incurred.
I have to repost the item
You mean relist it on ebay? Actually, when you report the buyer as non-payer then I am pretty sure you will automatically get the sale fee back, no further steps required from you. Relist after you get sale fees back. Both steps (reporting & relisting) are very fast, they aren't a faff imho.
Non-paying bidders is a top complaint for ebay sellers. Make sure your buyer requirements screen a lot of them out.
This thread is useful.
tbh, I stopped caring about NPBs years ago. I don't report them. I don't care if they don't pay. It's literally no skin off my back to deal with. However, unreasonable feedback or scammers: people who buy something then complain later about something in the description or condition they didn't understand even though it's written in black and white OR who I think have scammed me (claimed item didn't arrive, always high value never low items even though I packaged them the same; claim damage even though I suspect the evidence). THOSE practices annoy crap out of me.