Question:

If some one or government lends you some money which is the price of some
good today and we return the money as the cost of that good at the time we
return (which is a different amount), is this considered riba?

Answer:

A cash loan has to be repaid in kind, in exactly the same amount and
currency that was given. However, if they goverment wants to sell you
something, and you pay them on a delayed payment schedule, that is
allowed.

It seems from your question that there is more than one transaction taking place in this exchange. What is prohibited is any loan that brings a guaranteed return or benefit to the lender.

And Allah knows best.