Need Help Adding upgrades please!

I want to add the ability to collect coins, (I know the logic for that already) and once you clear the level you have the ability to buy an upgraded ship, if you have enough coins. Thats where i get lost. I posted a link for my game. If you have time I would love some help! Thanks!

Okay, the game is absolute pefect.

Graphics are nice
Controls are smooth
In terms of upgrades, you can save the amount of money you have
And when you get enough, you can subtract it and get the upgrade

Outstanding Graphics M8, awesome!

Might want to work on that grammer though…

Thanks guys. Yeah, its still a work in progress. Ive only been using flowlab for 4 days now and Im still getting the hang of things. @jngthree would you possibly have the logic you could show me? Thank you for your help!

@jngthree Sorry to bother! Do you have an example of how to subtract from the score? Also could you take a look at my game and see if you can spot why its not saving the score correctly? I would really appreciate it. Ive spent 4 hours now and cant figure it out lol Maybe @grazer can help? Heres the link to my game

The simplest way to subtract from a Number value is to increment it by a negative number. Example here:

Remember those pictures i put on your other thread? Thats how you subtract too