First time driver/car buyer. Numerous questions.

You've no comeback at all from a private seller. A private seller's price will (should) usually already be cheaper than a dealer (for the same car), partly because they're not offering any warranty.

You can offer what you like to a private seller, for any reason. How willing they are to take it depends on how much they need to get rid of the car, how much interest there is in it, and what's the minimum amount they have in their head for its worth (or that they've already budgeted into another purchase or use). I'd doubt you'd get a grand and a half off a car priced at 7k unless it was demonstrably overpriced, or you uncovered a significant issue. But I could be wrong.

The second hand market is pretty tight at the moment - more demand than supply. I was recently looking at cars from dealers, and none of them would budge at all on price. Not sure if private sellers in general are as sure of the market to do that.

I've never bought from a private seller, but I have sold as one. From that perspective, the only tip I'll give regarding haggling is make sure that the seller knows that you're willing to walk away. I had a couple who got a 3 hour train ride to come to my house to see a car. I picked them up from the train station in it, and let them dive it back to my place. In conversation they told me they only bought a one-way ticket. We had agreed a price on the phone, but when it came to them handing over the cash, they wanted to knock €500 off. I knew full well that they weren't going to walk 2 miles from my house back to the train station, pay for another two single tickets and sit on a train for another 3 hours contemplating the day they'd wasted. So stuck to my guns and got the agreed amount with little fuss.

General tip is to bring someone who knows about cars with you to check it out. If you don't know anyone, there's mechanics/companies that will do a pre-sale check for you that may uncover issues or confirm everything's fine. I've never used one myself.

A high percentage of "private sellers" on donedeal are nothing of the sort, stuff dealers don't want to stand over, backstreet dealers and boyos shiftin' cars all day long are rife in the private seller category.

They don't even bother to hide it and scumdeal make no effort to stop them.

"Private seller" ad I saw a few days ago; description: Just taken in from main dealer. Next ad I looked at: clean car, trade-in.

To be fair there’s plenty of decent dealers around Ballymount/Naas Road etc. I know some of them personally