Yes, I do develop custom application as per your requirements. I have developed many business applications. I have experience in developing the apps to manage stores, inventories, money/accounts, trips and many others.
Yes, I do provide custom modification to my scripts @ $30/hours or a fixed price quote can be generated upon receiving the detailed version of requirements.
Currently I am selling all the scripts at Envato Marketplace. Click here to see my portfolio.
Currently all the licenses are managed by Envato Marketplace and I am unable to offer any discount. The price at Envato Marketplace is very affordable.
Once I start selling scripts here, I will offer discounts to all the purchaser.