Context: I very much like the philosophy of get it in the hands of the users ASAP so you can start the learn-adapt-rework-tune-retune-joy cycle.
In that context, I have comments to extend the (great) suggestions Simon made: You may want to charge these users your projected full rate, then credit back virtually all of the amount as a discount offered as an inducement to participate in early testing. Having them pay you $10 after a discount of $9,990 of a (for example) $10K fee has multiple benefits apart from the ones I think your counsel will describe:
1. It allows you to tell clients that your pricing has been consistent from the start (or was reduced from $10K annually tp $7.5K or whatever), which avoids some nasty negotiating tactics where clients can come from emotion ("i want the same deal you gave him!").
2. Telling them that their help is worth almost $10K reinforces that both the software and their time are important and valuable, as opposed to getting something for free, which means that it may be worthless. The cost is the same but the value statements and mood change dramatically.
3. It provides consistent Marketing positioning. As noted by Simon above, the license is valued at $10K so brand value is upheld, and you can also place a term on the license so the free support can last quite a while without being perpetual.
4. Give you recourse (with attorney help) if someone does not in fact take part in the testing and you want to get materials, etc. back: you can revoke the discount for non-participation and then waive the $10K they owe you in return for getting what you want and a signed continuing NDA.
Hope this helps!