I shopped HARD and got mine for under $900. ($870-ish) That took about 2 months and an ass load of eBay whoring.

Here's what I think each figure is worth

00 Optimus Prime - $200
01 Jazz - $40
02 Prowl - $35 *
03 Skids - $35 *
04 Tracks - $40 *
05 Smokescreen - $35 *
06 Megatron - $125 *
07 Sideswipe - $50
08 Inferno - $30 *
09 Starscream - $70 *
10 Soundwave - $125 *
11 Astrotrain - $40 *
12 Minibots - $70
13 Targetmaster Hotrod - $20 *
14 Hound - $30 *
15 Stepper - $20 *
16 Insecticons - $45 *
17 Blitzwing - $45 *
18 Soundblaster - $85
19 Perceptor $40 *
20 Kup & Wheelie $40 *

these prices include shipping. Anything with an * I can still help you find. (a few $ below the tagged price)