I believe the nitecore intellicharger(i2 and i4 series) offers you basically all of the charging features the d2 and d4 models do, just without the fancy display. Last time I looked, they were like half the price of the d series model. That could be something to look into if you are on a really tight budget.
Just to discuss, I don't agree...
Why? because it's more than just a display, it gives you the information about your battery, how it's charging, it's condition, etc. it makes up the difference in price with providing very valuable information, if the battery isn't charging right, old, this will show you that it's no longer taking in the "normal" voltage, etc. something that you can't get with just a few blinking lights.
(I have the d4) And since it can take just about any sort of batteries, I can put in my rechargeable AA or AAA to charge and check those too.
Not only that, but I've seen some people report having issues with the "i" series a lot more than the "d".