Too bad no one with Maxspeed springs has answered the call. If I were the director of marketing and sales for that company, the first thing I'd do is raise the price to $160 since the current low price creates a perception of low quality. I bet they'd sell the same number of springs because potential customers wouldn't be as wary if the selling price was closer to the norm. Hey, maybe these springs aren't the greatest, I really don't know - but on the other hand, tempered steel coil manufacturing isn't rocket science.
Somewhat related story - I recently found a internet supplier of high-efficacy Philips bulb pairs that charged 50% of what almost every other retailer was charging. This raised doubt - in fact, I was absolutely certain that the ad was incorrect (the price was for one bulb instead of two). I practically wrote this place off, but decided to call them anyway to confirm that the price was for a pair, and not one. Turned out that the price was correct and I ended up getting a great deal on these bulbs.
Careful is good, but follow up. Don't necessarily talk yourself out of a good deal because of an arbitrary, general approach. However I agree that if due diligence is not an option, it's safest to go with something that's recognizable and popular with most forum members.