Hi spudgun,
Forum members arn't really encouraged to discuss pricing so I will try and help on the materials costings then simply add on what you would expect to earn from the labour and materials and go from there.
Firstly and most importantly worry about the substrate, ideal conditions would be one single surface, flat a as a pancake with skirting boards removed, oh and not too many awkward cuts. If your using fully vitrified porcaline if the floor isn't great it will cost you a fortune in addy and time spent, 1mm on these tiles makes a massive difference so leave yourself pleanty off time for laying. If you have to start packing out or dot n dab you will soon run out of adhesive. 260 tiles works out at 65sq m, hopefully you have got at least 20-25 for wastage.
For 60sq m I would estimate 3-4m a bag plus a couple of bags just incase. That equates to roughly 20 bags. Dependant on your grout joint I would estimate 15 - 20kg of flexi grout. The surface will probably need priming the day before and the tiles will need to be sealed and grout joints will all need sealing the day after.
So here goes...
Materials
20 x 20kg bags of Single Part Flexi in WHITE! (avoids shadows in your grout)
4 x 5kg flexi grout (eg Mapei)
2 x 1 litre Lithofin FZ Impregnator (for sealing)
Paper towel for removing sealant residue
2 x decorators mini-roller and tray for priming and sealing
1 x 1 litre of primer suitable for the substrate your working on
Consumables - spacers, sponges, cutting blades etc
Hire cost (or borrow) of a adhesive mixer, mixing by hand is hard going and slows you right down
Time
I would allocate a couple of hours in the evening before to clean and prime the floor. 2 long days to
tile, three days would probably be better if this is your first big job, a day to seal, grout, re-seal and to clear site.
Hope this helps, ps make sure the quote has three zeros behind it
cjbombero