I checked the sites mentioned and so this will be basically a system which sells the tips and as per discussion with my team we can build this with codeignitor framework for OOP. The advantage of lightweight framework is the site loads in 2,3 seconds. The complete back-end will be provided for manage users, tips, manage content and etc.
As per my understanding the project is not that complex. though the small things would take lots of time. The things have to handle are basic raw things and not complex calculations.
For the payment gateways we can implement paypal and any other payment solution you like. with paypal integration you can accept direct credit cards + paypal transactions. All the payments first goes to the admins account. you can charge some percentage from each sale a tips seller made. and you will do a mass payout every week or twice a week to tips sellers.
The system will have 3 different user levels. Admin, staff, Seller, And buyer. The all un registered users are will be Guest users. Staff users can manage sellers, buyers and handle support tickets. Admin user can create staff users, manage all the content including tips.
We provide support and service upto a year free and after the year period with a small fee for maintenance. This maintenance basically include security upgrades, upgrades with other depended technologies and etc. I'm very much like to discuss on this with you and start the project.
Thank you
Patzz