What problem?

Passages contained in "The Chapter on Money"
such as
"Because price is not equal to value, therefore the value-determining element - labor time - cannot be the element in which prices are expressed, because labor time would have to express itself simultaneously as the determining and the non-determining element..."
brings me to question, what was (is) at stake in all the time and effort spent on the "transformation problem"?

For me this was never a point of big concern as prices and values are two separate things that do not exclusively determine each other. Value is in use or exchange (which can differ) and is loosely related to a starting point of examining price, but no mathematical correspondence seemed needed or possible.

Why then all the time spent? Is it a response to the neo-classical marginal products of capital and labor argument, or something beyond this. This would certainly add importance to the issue but I still do not understand the necessity of showing that one constitutes the other.

I do not argue that commodification, and the exchange value relationship as well as commodity (or non-com) money become very important from producers of commodities, but I what I am reaching for is what is at stake saying that price and exchange value are not the same thing, and there is no reason that price can not deviate based on factors outside of the direct exchange relationship.

I ask out of my own ignorance, because I know this has been a very important thread within certain currents of Marxism, and I have not taken the time to understand it up to this point.