If you live in a medical state, buy ALL of your glass from your favorite club or dispensary/collective.
Head-shops are notorious for doubling and tripling wholesale cost of glass.
For example, just yesterday I saw a beautiful oil rig for 95$ at a dispensary.
The same exact rig at the local HS. .210$
MOST dispensary shops only mark up the glass about 5% if that, I've been told by many budtenders that they do this as to provide access to quality glass, so their patients can medicate properly without getting robbed by the head-shops.
Edit: you do not need anything fancy, simple in-line perc works perfect.
I only spent 80$ for the rig, but I did upgrade both nail and dome/110$ total for rig adj. Ti nail and dome. Just don't want some fuck working on commission, telling you, you'll need this that and the other.