Not that I've ever purchased PdCl
2 or para-benzoquinone, but the former can be had for under £25/g if you buy 25g at a time (but around £45 for 1g), and the latter shouldn't be much more than £40/kilo.
Be aware that they may be watched over here; the UK Government haven't published their entire list of watched chemicals, but it'd be safe to assume everything contained in
Post 404441 (missing)
(psych0t1c: "Precursor/chemical control in Germany", Law and Order) will be on it.