shimming hydraulic roller lifters solid

Was just looking at prices... it gets pretty nuts.. full set on ebay for $289... upto 1500+ a set.. Is the power gain from solids justified for that kind of cost? or only if you are trying to get every last hp out? i can't see 1500 for 10hp is that's all it is
....and those chinkese for that 289........I've emailed that seller and they SWEAR those lifters have pressurized oil to the rollers.