$10 ea plus USPS shipping. These are marked as 12.5 uF but most of them I measured were way closer to the 12.0 uF to 12.2 uF range. Here is what the Humble HiFi site had to say about its brother (ASC X386S):
ASC X386S MKP in oil 600VDC - 10% tolerance
Technical specifications: Industrial application capacitor. Although the tolerance stated is meant to be a poor +/- 10%, I measured all of them and they were all spot-on the stated capacitance. Now that is what I call built to industrial standards! I guess they state such a large tolerance because being designed for industrial applications they will be used in varying temperature conditions. The vegetable oil inside will therefore vary in fluency. But at normal room temperature they seem to be at their best. The values are different to the standard range but they come in values from 1,0 to 60uF although small quantities are hard to get unless you want to order more than a hundred of them. ASC also supplies these metallized polypropylene types to other notable High-End Audio companies, including Conrad-Johnson. ASC polypropylene and oil capacitors feature a sealed metal 'oil can' construction and hefty four-way solder/connector lugs on the bottom. The capacitor itself is made of metallized polypropylene film, similar in construction to standard MKP's, but suspended in a bath of vegetable oil: some claim that this oil provides a damping effect in audio circuits. When you shake it you can hear the oil splash around!
Sound: They sound a bit dull at first because they take a while to burn-in. But after a few days of normal use they deliver a wide and open sound stage. Nice and neutral, maybe a slightly warm and lush sound. One of those things that don’t impress at first but sort of grow on you after a while, you learn to appreciate their qualities - great! If you want a lively and bright sounding filter then this is not your cap (try a Hovland Musicap instead), if you are looking for a smooth, warm and relaxed sound then give these a try.
Brand/Series : X387S Series
Capacitance : 12.5 μF
Length : 3.875-0.125⁄+0.063 in.
Length, Lead : 0.5 in. (Max.)
Material, Element : Polypropylene Metallized
Temperature, Operating, Maximum : +70 °C
Temperature, Operating, Minimum : –40 °C
Tolerance : ±10 %
Voltage, Rating : 370 VAC