Its hard to imagine anything having worse performance than a Luton Minor! There are lots of VW powered aircraft, some better than others, but they should all cost about the same to run. If the FRED costs a lot less than other VWs, then as yourself why.
When FRED is flying it should be great fun flying for small ££, but I would recommend that you fly within a group to keep the costs and time commitments to a minimum.
Some other VW single seat aircraft to consider:
Tipsy Nipper (Aerobatic!)
Jodel D9 Bebe
Turbulent
Taylor Monoplane
Luton Minor
Evans VP1 (or 2 seat VP2)
etc. etc. etc.