Help with detector purchase!!!

I was wondering if anyone here was familiar with both the old Minelab Sd 2000 and the Infinium? I have been wanting a pulse prospecting machine and the 4500 and 5000s are out of reach for me right now and my sand shark doesn't cut it.
I have the opportunity to buy both used at this time. The Infinium in the $800 range and the Sd in the $600 range and it comes with allot of extras including large and small DD coils.
I know the SD is 16 years old but have read that it was a depth monster in it's day, however is not sensitive to small gold. When it comes to small gold I have my Gm 3 and Gold Bug to partner with it.
Is the Infinium close in the depth department to the Sd?
I guess my question is where would I get the most for my money?
Any help would be greatly appreciated.
Thanks In Advance

Heck all we have in my neck of the woods are coal nuggetts so can offer no help but personally if I lived in gold country would look for something in the Tesoro line as I know their land units just love gold jewelry...and service is second to none even with older units...

IF it's possible.....can you air-test BOTH units with a 1-gram gold nugget.........or a small target? This would give 'some' validity to the units.....as well as a functionality check.

Thanks guys for your responses.

Tom,
If I make the drive to go check out the SD ( 2 hourseach way ) I will test it with a 1.2 gram nugget I keep for just this kind of thing. I was just hoping to get some info before taking the drive. I know you have used the sd 2200 and stated it was one of the most powerful machines you have used. I also read that with the mods you can do to the 2000 it will get the same depth as the 2200. The Sd Im looking at appears to be moded but the guy is not sure as it was his dads who passed.
I guess Ill just have to give it a try.
Thanks again.

Just got off the phone with the Sd owner and seems their was a error in his add its actually a SD 2200 v2 so Im there tomorrow.
Whew HOOOOO.

Good! I'm more inclined to lean towards the SD-2200 vs the older SD-2000. It is a very powerful unit.....as long as it is functioning per design. This should be worth your trip.....and testing. Try to bring a small white gold ring....and maybe a open-hoop gold earring also....if you have one.

Thanks again for the input and test recommendations, It seems to work perfect but I was not able to ground balance well as his property had allot of iron in the ground. But the air tests were great. With all the extras I think I got a awesome deal. I did not have any white gold to test with but it picked up both the nuggets I took very well. One I have not weighed but its probably about a 10th of a gram and the other a 1.2 gram picker I found with my gold bug. Now if it would only stop raining so I could start training on it. I see a trip to the desert in the near future.

HH
Jim