receivers run about $59 (itm/oow) to $200 (globaltrades hungarian).

rivet sets run $20 or so (k-var).

riveting tools can run as little as $20 for a punch and some home made bucking bars to perhaps $20-40 for an air chisel that can be thottled back and used a a power riveting tool.

a small drill press is what i would call madatory. a complete set of metric drill bits is also nice to have on hand.

a good 6" machinist's scale, files, stones, a dial caliper and the usual assortment of hand tools round out the ak builder's toolbox.

many guys will say how much they like having an oxy-acetylene torch around, also.

ak's have been successfully built in 8 hours by a first time builder with nothing more than the usual tools found in the average suburban garage and in fully kitted out machine shops...and everything in between.