Since buttkicker has virtually no presence in Europe, we get small scale dodgy importers who charge 4x normal value.
And even in the states they are considered mostly "OK" value, but a bit on the pricy side compared to what they give compared with cheaper options.
They are and have been mostly trading on their name, and the gamer is a nice bundle granted that.
But there are more types of transducers out there.
Just google for Sine live or the Dayton mini-transducers.
They only cost around €15-20, granted you would have to source and amp etc, but they don't really need anything special, as long as it is rated for the given load, in short don't put an 8 ohm minimum amp on a 4 Ohm chain and blast away.
Just dig up any old amp with some juice and a frequency
low-pass filters like those found on ebay for a tenner.
If you mount and tune the transducer setup correctly, and I do not say that lightly, this is going to be harder than your average multi sub-woofer calibration,
I'm one of those who think six hours would be very fast sub calibration.
Only compounded because you can't use your normal tools, especially microphones
However the main problem with a transducer setup is much more fundamental.
Subwoofer feed is exceedingly ham-fisted, it's like getting hit over the head with a bag of bolts and then answer what size the various bolts where...
We shouldn't be using a sub-woofer output signal at all, this needs its own signal to really be any actual good.
A controller vibration feed would honestly be better than a sub-output..
The solution is simply motion feeds, a lot of the x-sim community seem to already be running this in a multichannel transducer setup, taking feeds made available directly from the game.
Some channels feeding smaller inputs like road bumps, another channel engine RPM etc etc.
And of course their motion rigs do the big stuff..
I might have digressed a bit, but we
need FD to supply a real motion feed that can be used VIA X-sim..