If this helps - my .co.uk psp domains are starting to show traffic (been a long wait), but click throughs are very low, so of very little value at the moment. psp related .com are showing more click throughs (per visit), so far. Rev. so far has been very poor - I don't understand why.
They should be worth much more than the reg. fee if/when psp takes off.
I would ask low - mid xxx and wait a long time, but devolop at few aff. links in the mean time - thats what tends to pay (for me), for this sort of domain.