All countries by bus?

Im going with King Quality bus from El Salvador - Honduras - Nicaragua - Costa Rica (San Jose) (and then I fly to Panama from San Jose, but ive heard The Panama Express bus is really good too). 65 usd one way, 18h. Check their website if you find anything interesting as they have many routes, and my local friend who is in the transportation industry told me that this is the safest bus company she knows. www.king-qualityca.com

The border crossings of what I know is something like 3bucks for Nicaragua and some countries don't charge. Not so sure yet, but the bus guy told me something like this... Just be prepared with american dollars and you should be fine...

Why do you want to take a bus thru each country and not enjoy them? The capitals are not places most people enjoy and usually try to avoid. They are dirty, congested and crime ridden, walking around with all your belongings as a foreigner in a capital is not to swift, and most areas around bus stations are dangerous, best to taxi.

Most people take 2-4 months to see this region by bus, I see no point in riding a bus to just look thru a bus window in the region? At minimum you need to allow 10 days per country, and that would allow you to see maybe 3 venues/highlights per country, depending on your interest, which at this point, is congested, polluted, grimy, gritty diesel smoke filled cities.

I think you would enjoy Leon Nicaragua and Antigua Guatemala much more...

This is just a first visit and I want to visit the most representative city of each Central American country. I learn a lot by just people watching, tasting the local food, see how cities organise themselves (or the lack of organisation, chaotic cities are enjoyable too:) I like to walk around and feel the vibe, talk to locals. I would visit Tegus, Managua and San Salvador daytime, trying to be safe. Obviously I would try to leave my backpack in a locker at the bus terminal, by the way, do you know if the bus terminals have lockers? or an office to mind bags?

Ticabus has hotels at their terminals with San Salvador's San Benito terminal being in a safe zone.

Of course #4 is offering useless advice as he's never even visited El Salvador.

I didnt offer advice on El Salvador.

When I bussed through C.A. in 2006/2007 from Guatemala to Panama the only country that we had to pay to enter was Honduras, I think it was $3.00 U.S.

I thought Nicaragua had a entry or exit tax of like $13...

$12 entry fee into Nicaragua, $2 to exit.