It can be a fairly nerve wracking experience to get off the pirogue in Albina, lots of people jostling for your business, taxi with me, let me take your bags etc etc, there has been at least one occasion when I've seen one bag go one way and another go the other, but genuinely the guys there just want you to go in their cab - price is 15 euros per person (or equivalent) in a car and between 5-10 in a minibus - Thats coming from French Guyana.
Going to French Guyana is not so bad, its a question of getting a pirogue guy of which there are lots, the price is 5 euros to cross per person, pay no more and some people won't accept Surinamese dollars, they prefer Euros, but if thats all you've got, it's there tough ....
Unique Suggestions: Going to Suriname, ask the pirogue guy to phone ahead and book a taxi man for you, he'll have a mobile phone, its probably best to do this before you get on the boat. This way, when you arrive in Albina, and everyone starts jostling for you, the pirogue guy will tell them that you are already with someone and everyone else generally leaves you alone.
Fun Alternatives: There isn't one budget wise, I think they've re-opened flights between Paramaribo and Cayenne, but this is probably far more expensive than the 20 Euros it will take to get from St Laurent to Paramaribo, even if you take a taxi bus from Cayenne, it'll only be 45 euros all in.