A lot
The bunker buster bomb is a very large bomb that either blows up the bunker by exploding directly on top of it (if the bunker is at ground level), Or if the bunker is a few feet below ground, the bomb will go through the dirt and explode in the general area of the bunker and destroy it. The bunker bombs of today, that are dropped by the F-15E Eagle, are much more powerful than the bunker buster bombs that were dropped in WWII by the English Avro Lancaster bomber.
This answer would depend on the type of stealth bomber you are referring to. Most countries keep their stealth programs classified, so it would be difficult to give an overall perspective. The B-2, built by Northrop Grumman and used by the US, is about 172 ft wide and 69 ft long and 17 ft high. It is relatively large if compared to the entire spectrum of military aircraft. The now retired F-117, was smaller, 43 ft wingspan and 65 ft long, as an accurate precision attack bomber. The F-22 and F-35, technically multi-role fighters, are both around the same size. Strategic bombers are being developed by other countries, such as the Tupolev PAK DA and J-XX by Shanghai Aircraft Corporation are being developed at this time. Their sizes are mostly estimates and kept under wraps.
Atom or atomic bomb is an older term. The modern term is Nuclear Weapon or Nuclear Device. Then of course there are Thermonuclear weapons (typically these are the large strategic nukes), which are also called "Hydrogen Bombs". These typically consist of a primary or trigger, which is basically a small nuclear weapon. This tiny nuke sets off a larger secondary inside the weapon which causes a fusion reaction and a very large explosion.
Because of there stealth.
A lot
If You are asking about the price of B2 Stealth Bomber, then its about $737 million (1997 cost for each aircraft, $1.01 billion today). And the program cost was about US$44.75 billion (through 2004). Source: Wikipedia
I heard it was somewhere in the vacinity of 250,000,000 Pretty pricey
For FY 2008 The B2 bomber's estimated cost is Approx. 2.2billion dollars each.
$81,947.62 approximately
about 50 million dollars
about 50 million dollars
Lancaster bombers cost approximately 48,500 Pounds each.
a simple pipe bomb can probably be built for $20.
About 31 grand if its "da bomb bomb"
A lot
£5