silk screening???

[kirstywoo88.livejournal.com]

Alright, so I found that great info about how to do silk screening using cheap materials, but I have some questions for those of you who screenprint.  I found some really cool screens online, they are made to be put in a lazer printer or a photo copy machine.  The heat like fuzes the screen where you print (so the black part of the photo copy) and BAM! you have a sceen and are ready to print in 30 seconds.  The thing is...they are kinda expensive. Like $70 for 20, and I can't seem to find anywhere where I can just buy one, to try them out.  Has anyone used these??  Can you give me some advice before I possibly waste money???