With that much pressure and those expectations, no contract signed, sounds like you are stepping into something you don't want to be involved in. I can easily see a court case, them saying how you didn't deliver and other things. I would say I'm sorry and decline.
But if it's honestly like that, that much pressure. The price quoted is way too low. Even for a amateur, with travel and such, editing printing. I'd do a good £2000, either they pay or not and move on to another sucker they can manipulate into getting cheap stuff.
Honestly it's not worth your time or stress with the conditions given. That's my opinion.
Muslin, might be an option. I'd say canvas a light one, could work. I do like paper as it looks good and is easily thrown away when dirty.