I heard this for first time and product is not free ( 140$ ) is not suited for marketing model here.
One frend send me link to check one tutorial and i found themeforest.
If template has HTML version , purchase it and put your own logic behind.
The trend is force to use bootstrap this days because clients are familar with system and want easy way to change and adapt template, if you base your admin theme in bootstrap you will get more sales this is fact. Other good trend is to base template in new metro flat style. Other template just not have a chance belive me or not.
Good luck denkGroot you are very good i advice you to convert your last template to bootstrap.
It`s no such things as fast money
I don`t care for stealing because in first time i obfuscated entire template, but after 2 new version i decide to not, and effect is more trafic and more sales yes more sales and more steal but i don`t care.