I think you got a good deal at 450. I bought several of those for work in oct of 05 they were 1800 +. I think you did ok. Your config (mem, hd ect) is good.
I would check out your battery's serial # at
https://www.dellbatteryprogram.com/Identify.aspx
All of the d410's that I have have a bad battery in them. It is very important to get it replaced, as it could catch fire. There is a defect in the design that a shock or vibration can cause fire. If you do have a recalled one, make sure to send your old one back so it is out of your hands.
You can get a usb keyboard if you find it too small to type on.
Those also usually have dial up modem and a network port so you can plug into whatever connection you have.
Enjoy.