Ok, I've been looking everywhere and have not found anything l can potentially use. How much would it cost to buy a jet engine with 300 lb thrust? How about 200? List all the different kinds please. l really need this!

you mean $200,000, l think if you were good at negotiation then yes

As u have discovered, small jet engines r not widely available, as they r used primarily by hobbyists & gadgeteers. Commercially manufactured jet engines for aircraft use start in the 10,000 pound thrust range.

However, if u will do an internet search on ''jet engine 300 pounds thrust,'' u will find some sites that produce such things for hobbyists & tinkerers. You can buy plans for less than $50 for building a turbojet engine based on a diesel engine turbocharger that u can build for less than $1,000.

Please note that this is a very dangerous hobby, & there r several ways to decapitate yourself or burn yourself to death. So be cautious. But have fun.