I would be a minimum of 19750 + vat plus all supplies on top, might chuck bin liners into price, but deffinately not Hand towels or t/rolls, mechanics are always wiping.
To be fair we do a couple of car showrooms, and cleans after a saturday or a bank holiday are very easy generally, usually just a few sales guys in, no office staff and only an odd mechanic in, so mechanics toilets canteen areas are still clean, and offices unused on the bank hol days.
14500 is less than £ 9/hr after consumables surely business suicide,
like Billy says, standards will drop, cleaning staff will leave early doing a poor job