NULL for subsequent lookups

[RollingStone88]

Hi.

The attached has two tables:

- A1:B6 is a lookup table which contains 'costs' related to a 'session'.
- E1:G10 represents 'items' which are all tied to sessions and there is often >1 item per session.
- The desired output is in column G.

Using column A, I'm looking to lookup the 'cost' value in column B to the first instance of a 'session' in column E. Importantly, once the first match has occurred (e.g. the 50 in G2), I want all subsequent matches to be zero (e.g. the 0 in G6). Is this possible?

Hope this makes sense. Thanks for any help.

[PaulM100]

One way: =IF(NOT(ISERROR(VLOOKUP(E2,$E$1:E1,1,0))),0,VLOOKUP(E2,$A$2:$B$6,2,0))