Ouch!! Oh well you're on holiday I suppose think you are looking at nearly a oner door to door! Once looked as was having one night in a hotel in Victoria and hotel would arrange a transfer at 88 euro!
The ferries run through the night. Look at transfer companies such as Malta Transfer or Resort Hoppa. Both offer a transfer whereby one driver drops you at Cirkewwa for the ferry, and another picks you up at the ferry terminal in Gozo and takes you to your hotel. This could work out considerably cheaper than the direct taxi mentioned by TheStath above.
Not that much cheaper in truth though trip's as I was rushed 30 euro from qawra to ferry then 25 from ferry to xlendi so there's 55...either way it's a nightmare for me as 23.35 is eta so conservatively add 30 minutes on (or 3 days if you are on s Michael O'Leary excursion) so post midnight etc first visit might..would say get a very cheap night in a hotel in qawra get the resorthoppa shuttle to qawra (pennies) then the bus to ferry(pennies) bus to wherever in gozo! That lot? 25quid? Depends how loaded the traveller is
Even during the night, most of the transfer companies will quote around £60-70 ( excl ferry fare €4.65 rtn.) return to your accommodation. Try Hoppa