Not sure what you are on about, but Spice and Wolf was inspired by a history book on the progressive transition from feudalism to capitalism.
This is shown through the perspective of a merchant via his economic relations to the market and the respective classes (royalty, traders, even the clergy) which manipulate it. The audience in turn gets to see actual economic movements in play all the while being connected to the human motivations which drive them.
You can make your case against against its presentation of these aspects or the quality of the anime itself, however there is one thing it is not. It is not capitalist (sic) wish fulfillment. Waifu wish fulfillment on the other hand...
There are much more egregious examples of actual capitalist wish fulfillment which Sp&W does not replicate. Take a look at Shield Hero for example. Unlike, Sp&W it does not follow any principle of economics outside of a gamified, MMO-like economy. The fact the protagonist is a merchant does not bare any weight of the power dynamics within the plot's conflict. Instead, the conflict is driven by often contrived reasons such as conspiracy or by deus ex machima (the shield hero prophecy shit.) Wish fulfillment tends to leave out the details of its subject, lest seeds of doubt are sown. And, in Shield Hero's narrative, those details are avoided through its premise.
Spice & Wolf's narrative on the other hand is put into a historical and economic context. Thus, making Spice and Wolf- in spite of its fantastical premise- the closest we have to a historically materialist anime.