If you pay by cash, it’s easier to understand how much things cost in this town.
If you pay by cash, it’s easier to see how much you’re actually spending.
If you pay by cash, it’s easier to understand the price of goods in this town.
If you pay by cash = 現金で払えば
easier to understand = の方が分かりやすい
How much things cost = 物がいくらかかる
How much you’re actually spending = 実はいくら払っている、どれだけお金出している
The price of goods = 物価
In this town = この街では、この街の
アメリカ合衆国 
