Caveat: I have only read Priceless, and have not actually played it yet.
Priceless is a nice, straightforward yet spooky LARP adventure. The writing and layout are well done, and character descriptions and instructions are detailed enough that even inexperienced players should do well.
In Priceless, your players get to play the role of young children, who notice that mom's not quite right today. This could be quite a bit of fun, especially if you've been playing more traditional roles for awhile. You need to solve the problem before bedtime, or bad things will happen.
Some minor gripes: Without giving anything away, I do think the conclusion is somewhat abrupt, and might leave players a little dissatisfied with the outcome. Also, the plot is somewhat linear, which may constrain more experienced players.
What I really like about Priceless is that, even if you're not a LARPer it's very good source material for such tabletop games as "Little Fears" or any other RPG featuring children as PCs. With a little effort, you could probably even graft it into more traditional RPGs too.
If you're looking for a LARP that's quick to setup and run, and some or all of your players are inexperienced, this is a good one to try. Even if your group is more experienced, the scenario would be easily customizable towards your group's tastes. And if you run a tabletop RPG with children as PCs, Priceless would drop in easily.
(Replies: feel free to contact me at kirk at rafferty.org if you have questions. I will not share the PDF with you, nor will I give plot elements away.)
[4 of 5 Stars!]