Most normal people would look at that and think, "Ah, so it's £950 eh? Right, I've gotta pay £500 up front, sooooo, that leaves £450 to pay over 5 months. Therefore for each month it's £450 divided by 5 which is £90 a month?

OR, the way you said it, it could be construed as £500 up front AND a payment too..... leaving the rest over 5 months???????? 

For kids, that'd be even more confusing.