Formula to check if values match or are zero

[SandMan20]

I'm working in Excel 2013 on Windows 7.
I'm working on a project to compare the prices on items between multiple sites, and I am trying to come up with a formula to check if all of the prices either match, or are blank (ie, a given site does not have an item).
For instance, I would like the following chart to count as a bad set,

site 1	5
site 2	5
site 3
site 4	6

<tbody>
</tbody>

On the other hand, the following would be counted as a good set:

site 1	5
site 2
site 3	5
site 4	5

<tbody>
</tbody>

Is there any formula that can accomplish this?
Thanks!

 

[MarcelBeug]

Suppose the prices are in B1:B4, then:

=SUM(--(FREQUENCY(B1:B4, B1:B4)>0))

will give you the number of different prices, so 1 for a good set and >1 for a bad set.

 

[SandMan20]

Great, that works! Thanks!

 

[MarcelBeug]

You're welcome.