With the recent changes to RP costs in the UK, the new £15 RP purchase is better value than the £20 option.
2525RP/£15 = 168.3 RP per £1
3350RP/£20 = 167.5 RP per £1
It's only a small difference and may be deliberate but surely if you're spending more money on RP you expect to get better value? We should be getting a little more RP for the £20 option for the pricings to make sense.
(This only applies to costs for debit/credit card and PayPal purchases)
P.S: Sorry if I posted this in the wrong place