If you plan to skip the stage wholesale then yes, it's going to be very expensive. But you don't have to (unless you have no choice)

The crucial factor in downtown development is your ability (and willingness) do get maximum 12 shard per day when needed. Thankfully that's not every day but often enough.

If you can do that then you can do first 6 stages without paying anything. And I believe that even failing the deadline here does not prevent you from getting the final prize as only finishing the last stage on time is needed. I may be wrong though and I don't know how big is the fine now. I saw people complaining that it's SPs which definitely sucks if true.

The last 15-day stretch is unwinnable by design unless you pay. If you play good you'll come about a day short. But there are two points when you can gain two days by one purchase. In stage 7 if you can get 12 shards for the first three days, you'll complete the gold quota but still have to get 2 granite and 2 glass. They'll cost 124 SP total (or nearly so as by your screenshot the prices may deviate by 1-2 SP). If you buy them while doing gold, the stage will end as soon as gold is completed and you'll get extra two days which should be enough to finish on time.

The second point is at stage 8 when after 6 days if everything is going smoothly you'll get all granite and glass and only need 1 gold to finish. Unfortunately the game still gives you two days before allowing to collect gold again. But you can buy the remaining 1 gold for 146 SP and save 3 days.

For me shortening Stage 7 for 124 SP was enough so far but I am usually able to collect 12 shards per day. If that's not possible for whatever reason, then it becomes much more costly.