s7 and scada

I want a project with S7-300 Plc including also Scada(WinCC or Winflexible).I investigate optimal cost.What I need for communication between plc and pc ( hardware and software)? .I have 225 DI,100 DQ
Thanks in advance.....

One offer came.
CP343-1 card for S7-300 315-2 DP Plc 86GK7342-5DA02-0XE0)
1024 tag WinCC ( 6AV6381-1BP06-0AX0)
CP5613 card for PC (6GK1561-3AA00)
Driver ( 6GK1713-5CB61-3AA0)
is it optimal cost?

If the communication is TCP/IP and not ISO, you don´t need the CP 5613 because you can use the ethernet card in your PC and the CP343-1 can be the "Lean" model. This way you ca save lots of money (1500€).

You can also save some money (and work!) by using the 512 Tag version of WinnCC Flexible.

Take a look at SIMATIC S7-mEC:
WinXP Embedded
Soft Controller - WinAC (functions of S300 series)
Works with WinCC Flexible too.
You will save on:
OPC,
Lean Ethernet card,
PC system block,
Windows XP.

A 315-2DP is a bit too small for a project with 225DI/100DQ.
Exchange the 315-2DP + CP343-1 for a 315-2PN/DP. It has more memory and the integral PN port is also faster. It is still a bit on small side, but at least better than 315-2DP. All in all also cheaper.

A regular Ethernet port in a regular PC will do.
So dump the CP5613 card.

For WinCC you need an RC license, and maybe an RT license. They are both very expensive. If you dont need all the bells and whistles of WinCC, then WinCC Flex RT is much much cheaper.
You will need WinCC Flex advanced + WinCC Flex RT 512 or 2048 tags + WinCC Flex archives or WinCC Flex recipes or WinCC Flex archives+recipes.
You possibly also need Simatic Softnet Lean.
With all this it is still far far less expensive than WinCC.

Spend some of the money saved on a good quality IPC for the Flex RT.

I would not chose the S7-mEC if you are a beginner with S7, or if Profibus DP is part of the project.