“Buy all the products you need while spending the least money on a busy and dangerous market.”
All players get the same list of products and are dropped into the same map ( = randomly generated market/set of shops).
You’re trying to find the products, but also the best deals for them. (The products are sold in many many places, so it’s never frustrating to find one, you just need to find the best deal too.)
There are extra products you can spend money on which are merely gadgets. Ways to help find stuff faster, to get lower prices for things, maybe to steal something once in a while, and to prevent against dangers like pickpockets.
Title “Saving Grace” is a pun. All players are called Grace and they try to “save money”. It also applies to the moment you finally find a place that sells the last product you need for cheap; that place is your Saving Grace.