As some of you know, the ability to download full kits at once was implemented only relatively recently. Full kits require a decent number of download credits to download, and are intended to be a "bonus" for people who donate to support Pixel Scrapper: people who don't wish to donate (or don't have the resources) can download most kit items individually for free as those items are uploaded (so you really can get just about everything on this site for free--for personal or commercial use: just not all at once).
The kit pricing is done automatically: basically the computer looks at how many items are in the kit, and then discounts the price of the kit relative to the download credits required to download the items individually. We're still working on the algorithm. To this point kits have required 60% of the number of download credits it would take to download the kit items individually. This seemed like a pretty good discount... still, we really want to give back as much as we can to people who donate to support the site, and some of the kit prices seemed a bit high to us.
So today Marisa and I are reducing the download credit price of all kits by 50%. That means that every kit will now cost only 30% the number of download credits it would take to download the included items individually (in other words, a 70% discount over individual item downloads).
Please realize that this site is still in beta, and this pricing scheme may not be final: we are in the process of experimenting. As always, our goal is to be as generous as we can be while still managing not to go bankrupt from hosting and bandwidth costs.
Thanks to all of you who have supported us by donating so far (if you would like to be one of them, you can donate here)! I hope you enjoy the new kit prices