charges of a simple desktop Point of Sale

[Saboor_1]

Hello to all! I have an order of a simple desktop pos which i will develop in java. Actually i have to develop this pos for a person who is owner of a hardware shop(nuts,bolts,nails, hammers and screw drivers etc.). He needs features as follows:
1-Automate his sales transaction i-e he will enter item, quantity and sale price and all the bill will calculated automatically.

2- He also wants to manage his inventory.
     After a sales transaction, stock of items should automatically calculated.

3- He want to analyze his transaction data . For example he wants to see his daily, monthly, weekly sales report and also want to see his profit based on items or time.

I have no idea about how much i should charge him?  Actually i have met him for the first time and just briefly talked about requirements. He asked me about charges and i said him that i will tell you tomorrow about charges.
So please guide me how much should i charge him for above requirements.

One thing more that he does not want printing function at the moment. So please guide me how much i should charge him without printer function?
I shall be thanks full to u.

[JamesCherrill]

That sounds like an absolutely standard little shop accounting system. It would be madness to pay for a custom application development and its ongoing support rather than simply deploy a standard supported off-the-shelf solution.

Here's the first example I found in a quick Google: https://www.manager.io
(Please note I know absolutely zero about that particular offering, it's just one example from a vast list of such offerings, and its free for a single user.) Are you going to compete with that?
Even if there is something genuinely unique about this particualr requirement I doubt that it would need to be developed in a high-end complex programming language. For data entry and some reports you just need a popular database.

If you really want to offer something in this case maybe you should offer to capture and document his requirements, and survey the market to produce a short list of 3 products that woud suit him. Without knowing where you are I can't comment on fees - daily rates vary beyond belief between different countries and even metropolitan/rural environments.

[Reverend Jim]

And you could charge him a fee for the installation and configuration and possibly a bit of training. If he is happy with the service he will likely return when he needs more help.

[rproffitt]

As others noted, you may have reasons to do this but my view is you should pick an opensource project and contribute to it's development.

Examples at https://sourceforge.net/directory/business-enterprise/financial/pointofsale/os:windows/