depending on how old the engines are you may be able to compare prices on ebay, some are quite valuable some not so much,I would also recomend posting some pics the group here can ID just about anything that's ever been made, built, or crashed there might be some value, and some might need be chucked in the bin, after pulling off what is valuable.

you might be surprised how small you can pack the parts in a box when there not in a airplane, servos,engines etc...are pretty small who knows.

could also be a score, some airplanes can be worth thousands of dollars