wat are garrett t04's worth??

i have 2 garrett t04 turbos that i was going to use in my 67 belvedere but with money time and space an issue i wanted to sell but have no idea what they are worth. they are used got em from a friend for a straight trade for an engine block but no longer need them they are not massive turbos but i bet will lay some serious power down. what do you guys think they are worth?? or wat would you pay for em?