Don’t pay for tune up. Get some lube and search you tube for how lube your bike. Take an old rag, q-tips and dust blower (kind you use to blow off dust on your computer keyboard) and clean the bike. Take nice pictures of the bike with good background. Post it best you can and see who nibbles. I will tell you, you will get some ridiculous offers mixed with few good offers.

If you bought the bike used you shouldn’t take that much of a loss. I bought and sold many used bikes and many I made profit from (never my intention).

best wishes