A lot must go on making this (7,5)
I believe the answer is:
reserve price
'a lot' is the definition.
Both the answer and definition are singular nouns.
Maybe they are linked in a way I don't understand?
'must go on making this' is the wordplay.
I cannot quite understand how this works, but
'go' could be 'serve' (serving is a kind of going) and 'serve' is found in the answer.
'on' could be 're' ('on' can be mean 'with reference to') and 're' is located in the answer.
The remaining letters 'price' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for reserve price that I've seen before include "value that may lead to a lot for relatively little" , "Bottom limit at auction" , "Minimum amount acceptable at auction" , "At an auction, the lowest acceptable bid" , "Lowest possible cost" .)