Very High Costs?

[Benneh]

I am sorry if this is in the FAQ but I needed to ask a quick question.

When I started my gameplay thee costs were low, about 40 grand for the first areoplane out.
NOW - The first areoplane is still on the list. and costing 200 grand! also, trains are very high prices, it costs me about 1 grand to do one piece of road, and I am not earning enough profit to pay these costs.#
Can somebody explain why these prices are so high? Thanks to all answerers.

[FHS]

Inflation

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Basically it means Moneys value decreases over time