What's that....cheap astrophotography???
Unless you stick to lunar and planetary stuff (and even here you can spend big), where you can get away with spending less than $600 on a good imager (Celestron NexImage...$300, DMK21...$600), it will start to bite hard in the hip pocket. Let's consider a baseline setup...
SWED100Pro...$899
EQ6Pro mount...$1999
Orion ST80 Guidescope (with rings and mount plate) $350
QHY5 autoguider....$380
That's nearly $3700 worth of equipment. Then if you want to snap DSO's, you're going to have to get a reasonable imager first up. You could go for a dSLR and if you look in the Trade and Classifieds section here, you might pick up a good one reasonably cheap. Or if you're going down the CCD imager side of things, you can get a Meade DSI (of one version of another) there too. If not, a DSI II will set you back $600, DSI III OCS (One Shot Colour) $1300. From there on, the sky's the limit. It just depends on what you can and what you're willing to spend.
Let's consider a reasonably good, middle of the road, setup...
Prostar 127WPF Apo....$3250
EQ6Pro mount....$1999
WO ZS70 guidescope....$549
QHY5 autoguider....$380
QHY8 Pro II Imager (OSC)....$3200 (or QHY 9....$3500 and QHY 2" filter wheel....$750, Astronomik Type II 2" RGB filters....$959)
There's nearly $9400 in equipment....$11400 for the QHY9 option. Then there's your laptop to run it all from, eyepieces and barlows/powermates etc.
Then, if you want to really spend the cash, it's a matter of take your pick and be prepared to fork out.