Most Costa Rican restaurant I went to have a 10% tip already included, I guess that's like their standard. But of course if it's good then too more. And you also have to pay food tax at the restaurant. So be careful with that (I think 13%). Standards lunch is about $7-$10 depends on where you go. So with drinks I say around $16 for lunch. You can always live off cup noodle like me. Tours can be pricy if you want to do activities like kayaking or zip lining. I say from $60s-$120. Depends on the number of hour you're going on these activities.
And then you want lots of gifts. That's where the locals get their money. Be prepare to haggle and shop around to compare prices. You have to learn to turn people down and look for a better price. Don't just give in if they offer you a "deal", because the next shop can have a better deal. Most small gifts costs about $6-$10. Exchange rate is about $1=
