Is the price of the nail really a good indicator of quality?
Some quick research I did:
A grade 2 Ti plate 12" (30.48 cm) x 12" x 19.05mm = 1770 cubic cm = $802
The grade 2 Ti data sheet. Density of Ti = .163 lb/cubic in =4.51g/cubic cm
Multiply this by the volume, 1770cc, and that plate weighs 7982.7g
Divide cost by weight, and you'll find each gram of grade 2 costs....a whopping 10 cents
My [small] 14mm Ti nail weighs 5.6g. Tripling that would probably be a good estimate for an average 18mm nail. So, a 16.8g nail would only use $1.68 worth of Ti. This number is certainly lower for big companies (such as HE) since they get better bulk pricing.
Since the cost of actual Ti is so low, it's bullshit to call a nail lower quality simply because of it's selling price. It is 100% feasible that cheap nails from less established and/or ebay retailers are in fact grade 2.
Stick a piece of grade 2 TI into a lathe and try and make a nail. It's hard and brittle. Makes it difficult and time consuming to work with. You're paying for the labor and equipment to make the nail, not the titanium. They're also standing behind their product. If their nail makes you sick...you can find them.