Custom Web Application

We are currently looking to develop a solution that we can use on site on large events that allow our client to login to a web portal and manage distribution of Two Way Radios on site and be able to track two way radios and accessories within their event space. For example we'd like the user to be able to login to their event on our portal which we have pre-loaded with the asset/barcodes of the radios and accessories they will be receiving to their event from us and then they can sign radios & accessories out to users on site by entering first name, last name, department, contact number and then have the ability to scan by barcode the items that are assigned to that person. There should also be the ability to add an item if it isn't in the database OR enter manually the barcode. This way as radios are returned at the end of the event they can scan radios back in, this can be a bulk scan in and they are then marked as returned from that user and be able to be re-sent out to someone else/marked as available. It also should then be able to generate a report for the event organiser as to outstanding items per person so they can then use the contact details to retrieve the equipment back. I'd be interested to know what pricing would be for something like this? This would need to be web based and have the ability to have multiple events/projects run independently and simultaneously. It should have an admin section for us to be able to setup the event and provide login details for the event organiser. I look forward to your thoughts.