LOVE stamps! I make my own to use in collages, some hand-carved, but I also make photopolymer stamps from my illustrations (you can capture a lot more detail). Here's one of mine... http://magicjelly.com.au/blog/images/2009/02/art-fights-fire-collage.jpg
& another couple of eeny-weeny ones http://magicjelly.com.au/blog/images/2009/02/little-collages.jpg
I used to sell stamp kits too, but I haven't done that for a while.
I'm just really into low-tech printing processes (I own 4 goccos!) & love paper & ink. I'm not sure where would be the best place to buy cheap vintage stamps other than Etsy & Ebay. Scouring local markets might be more time-consuming, but will probably work out cheaper. Love those little vintage type sets, but you usually get missing letters.
As for exactos...I almost lost the top of my thumb cutting a stencil a few years back. Ouch!