I’d suggest make him an offer for the important bits but leave out the tube itself on the basis you assemble one for yourself locally, ie
- mirror and mirror cell,
- secondary mirror and spider,
- focusser.
Just be thoughtful as to whether you trust international delivery with such a bulky piece of equipment. You'd be surprised how roughly parcels are sometimes treated! Furthermore, with classified ads there isn't anyone to risk getting a bad reputation if they send something broken or dodgy and don't reimburse/fix.
Good luck with your purchase...sometimes a little risk is the spice of life