Design roller coaster in-game "sandboxed" (not pay until completed)?

[tshorts]

Played this beautiful game on and off since 2002 and just picked it up once again. 

I quickly remembered the biggest flaw of the game; that when you try to design a unique roller coaster adapted to the map they always end up at least 2x more expensive due to extensive adding and removing of coaster building blocks until you get the fit you want, do a test drive and have to do changes because to high intensity or G-force. Ending up with 20 mill for a 5 mill worth roller coaster. Soon ending up just pop a prebuilt because it's easier. 

 

So, is there a mod / plugin so you can build and test the roller coaster in an active game, but not pay until you've accepted you want to use the coaster, and then just pay for the material actually used?

[jensj12]

When you design a rollercoaster, demolishing track pieces comes with a full refund, but only if you haven't opened the coaster before (then it's 70%). You can simply build and design you coaster freely, only paying for the final track design and the terrain/scenery lost in the process. If you need to edit a previously opened coaster and don't like the 30% cash penalty, you can refurbish the ride first.