I need to customise the Vtiger open source software to include the following functions:
1. Create markup in price book which will allow list price of product in each price book to be updated from unit price.
2. The price book will be automatically updated when the unit price is changed.
Quote only if you have experience in this and if you are able to support for future upgrades. Please make necessary changes to a fresh installation for trial purpose before doing the necessary on live site. Thanks.