Here's What Will Happen
If Jundroo Added In-Apps Purchases, Players would be Upset About The Parts, The Slots Are Limited, And A Maximum Of 10 Mods, On YouTube, Some SimplePlanes YouTubers Upload that SimplePlanes had In-App Purchase, Out Of The Website, They Would Get The Full Game For Free
In-Apps purchases
$1.99 Infinite Mod Slots
$5.99 Infinite Airplane Slots
$10.99 Get Full Game
$2.99 Remove Ads
The main thing if SP had an in-app purchases is, just like Juno mobile, it will becoming free to play but some features is locked and you have to buy some of those extensions with real currency.
Since the game itself is not free to play as you need to buy it, well this isnt worth it
imo, That would feel too expensive for an aging game like SP, and seeing how ppl who dont have the money would have to spend more than the games worth for full access, not sure its popularity would recover
but thats just my 2 cents