Ughhhhhhhhh sorry guys, I've cocked up.
My ~fancy~ spreadsheet was only supposed to count people (to work out cost per person) if there was a value in the deposit column, and it didn't, it included everyone (including people who said they were interested but didn't pay a deposit) so it's £90 per person rather than just under £80.
Massive apologies for the inconvenience for those who've already transferred what they thought was the remaining balance last night or this morning.
So, just to confirm: if you've only paid the £20 deposit, you now owe £70. If you have paid the £80 you need to pay another £10. There's no rush though.
Again, I'm sorry.
Not having a very good week here. Should have got Kovacs to the do the spreadsheet!