Hi Albert
Sorry, cannot remember the cost of the mini van.

I took a boat from Portobello to Cartagena three years ago - $400 - nothing extra for the bike.. I went in February when trade winds make for rough seas. You could check on current conditions. I thought it was a great trip. The San Blas Islands were worth a bit of puking.
Cheers
Will

@Cheerfullpedaller: Thanks anyway. If I fly, I may attempt to cycle to the airport and then package the bike there.
@Will: Cheers, mate. I think prices have gone up since then. Not found anyone who'll take the bike for free yet. One company wanted $100 to take the bike on board! If you go the small boats along the coast route (and not with a yacht) apparently you get charged double: once for the bike, one time for you. That's what I was told it would be for the Colombian border to Turbo leg of the journey anyway.
Seems want ever route you choose it's going to be a fair bit of hassle. Really don't fancy the puking.