I thoroughly enjoyed Happy Hour of the Damned (having won a review copy from Mark, which he signed for me). I reviewed it on UK Amazon and added it to my Listmanias.
I don't think the cover price helped him but I also think he was just unlucky - Happy Hour came out just before all the interest in P&P&Z and Forest of Hands of Teeth made zombies bigger business, so it went under the radar a bit. It's a real shame because they're funny, quite black books.
I've previously looked in UK stores for Road Trip, but haven't found it over here, but shall redouble my efforts.
MM