The spinnaker certainly would be more expensive to install but you will receive supercharging equal to the extra money! :-). I real rough 'ballpark' breakdown of pricing would be as follows and assumes that you will be doing the upgrading work with new hardware. Particularly with the range on the spin pole / snuffer system it depends on how much you build yourself or if you are buying a system 'out of the box'.

Oh and BTW, you should really take Eric up on that offer for a ride! He's got a great boat.


Jib:
jib: ~$550
Bridles / Forestay: $100
Halyard and hardware: $40
Jib sheet and blocks: $120

Spinnaker system:
Spinnaker: $700-800
cordage: (halyard, tack line, sheets): $160
Pole / Snuffer: $150 - $800
Misc Hardware: $60