The cheapest jetengine so far i have seen, a swedish made one. Costs 19000 Skr/ 1750 Euro if my calculation is correct. An electric engine (ducted fan) with enough batteries to power my aircraft would cost about half that much.
If i look at second hand, then i will get away cheaper. But then you have to be aware that it has not been in a crash or been runned overpowered/overheated.
There is so much to think about before buying anything. Like compitability between diffrent components, all the electronics inside the aircraft. The more weight, the less it costs. So its a delicate balancing between your own economy, good and reliable components.
There is much more to it then i first thought when i started with this project. Im a bit out on deep water but help is not far away if i ever need it. The restoration of the airframe is easy, to get it up flying safe in the air is the hard part.