Hi fellows,
I'm in a need of a very good Multimeter with an acceptable price tag!
I'm especially looking towards a multimeter with ability to measure current levels down to the micro and nano levels!
The more you ask the higher the price.
The cheap multimeter doing fine down to a few uAmps / milliVolts .
For nanoAmps/volts you need more specialized equipments as even the wires you're using can influence readings.
YOu should consider building your own measurement device (and connect to Arduino)
What's an "acceptable" price tag?
Let's toss out an example. An instrument I got to fondle briefly, many years ago. Given that amperage is measured by running the current through a resistor, and measuring the voltage, we can consider a voltmeter. This instrument is a voltmeter, not a multimeter.
The Keithley 182 can be had for about $2800+ used according to this small sample, and I don't know whether that includes calibration. On the 3mV range, it will resolve 1nV with a 1/60th second integration time.
Is that an acceptable price? Well, if you really need to make those sorts of measurements, then it probably needs to be. Are there other instruments which will do this? Sure. I just tossed that one out as an example. An HP 3457 DMM is about $650 with a NIST traceable calibration, but it won't do nanovolt.
I don't know why you need it except for constructing a death ray. But here you go:
The Keithley 2100 series is cheaper than the 182 for sure and reaches 10nA accuracy and 0.1uV accuracy. To get nV you need nano-voltmeters with the $3,000 price tag.
This might be a good solution: http://www.kickstarter.com/projects/eevblog/current-gold-precision-multimeter-current-adapter
Maybe you can order one of these current adapters on eevblog.com.
liudr:
I don't know why you need it except for constructing a death ray. But here you go:Benchtop Digital Multimeter (DMM) | Tektronix
The Keithley 2100 series is cheaper than the 182 for sure and reaches 10nA accuracy and 0.1uV accuracy. To get nV you need nano-voltmeters with the $3,000 price tag.
USB? Kids these days have it too easy. You should have to use the IEEE bus and like it!
sth77:
This might be a good solution: http://www.kickstarter.com/projects/eevblog/current-gold-precision-multimeter-current-adapter
Maybe you can order one of these current adapters on eevblog.com.
Shiny!
IEEE bus? GPIB?
Dav JOnes from EEVBLOG one is owned by our very own Nick Gammon
I thought to own it but then thought about any other good lcd equipped one!
Keithley is very expensive for me 
My dad spent his whole life on a sub 50USD multimeter! BUT then he never needed to measure that low on amps so he was always fine!
I think measurements till uAmp are fine for me!
liudr:
IEEE bus? GPIB?
Yes.
Initially known as the HPIB - Hewlett-Packard Interface Bus, standardized as the IEEE-488.
THe GPIB cable can hang a man. It's too much to handle. USB is soft and easy. Plus GPIB has about 1MByte/s data rate. Parallel buses are things of the past.
liudr:
THe GPIB cable can hang a man. It's too much to handle. USB is soft and easy.
Exactly my point! ]
Do you -really- need to measure down to nA?
Everyone wants a signal generator that goes from DC to light at 0 ohms output impedance with unlimited power and perfectly clean spectral output, to go with our all-in-one 32 channel 3THz 30Tsmps DSO/network analyzer.
But what do you -need-? As pointed out, there are ways you can add capabilities to a less expensive meter.
BTW, watch out for the really cheap stuff. Problems can range from unreliability, to hazard to life-and-limb. Look up "arc flash" and think about holding a meter with defective design and substandard construction while using such a meter to check a 240V outlet.