You right on the prices of this stuff. Lessemf.com
has some decently prices stuff.

For safety, I decided to put 3 mega ohm
resistors with a high voltage capacity (1.5Kvolt I
think) and an in-line fuse (.1 amp).

Even with people who are experts in the electrical
field, electricians and electrical engineers, there
is debate about the safety of earthing.

If it were me I'd at least put a few mega ohm resistors
on the wire for safety.

I've been using a little $4 strap with a mega ohm
resistor built in. Can't say on the frame or springs,
but an interesting idea.

Might look on youtube, some guy made it contact point
with a window screen under his matress.

good luck!