My list would be:
rent (or mortgage payments);
buildings insurance if you own the building;
buildings insurance very probably if you don't own the building - in many business premises lease agreements the leaseholder is responsible for buildings insurance for the building or their part of the building, this is normally paid by the landlord and then re-claimed from the tenant;
insurance of stock, public liability, employer's liability, etc;
rates;
waste collection* + you will have to budget for occasional disposal of things which can't be fitted in your sacks/ bin or which should not go in the bin;
installation of alarm system if you are going to have one + maintenance + monitoring if you are going to have a monitored alarm;
other security measures e.g. shutters, locks and any maintenance;
fire extinguishers and yearly maintenance;
business vehicle? Depends so much on the type of shop but if you will be collecting from places like Costco you need a big enough vehicle, parking costs if you need a vehicle and don't have your own parking space;
electricity, water, sometimes gas;
staff wages, NI, et, cost of someone doing payroll if you don't do it yourself;
other costs associated with staff e.g. uniform or protective clothing, somewhere to hang clothing and store bags and such;
factor in pest control 'just in case' N.B. If a pencil will fit through a gap e.g. under a door that is big enough for a mouse to get in;
cleaning including windows - cost for someone to do it, or cost of materials/equipment if self or staff do it;
rent of cash register if renting;
ditto card machine + ongoing costs such as the fee or percentage of each transaction taken by your supplier + cost of PCI compliance;
phone/broadband;
till and card machine rolls, paper bags, carrier bags, price tickets, tags for tagger guns, printer ink, printer paper, paper pads, envelopes, stamps, pens, pencils, marker pens, gold and silver writing pens and don't forget toilet roll, disinfectant/toilet cleaner, new washers for the taps and labour if you don't DIY. Maybe you'll want kitchen roll for quick mop ups in the shop? Cleaning cloths, tea towels etc have to be washed and replaced from time to time, sets of keys if you entrust them to one or more members of staff, bags for the vacuum;
milk? tea? coffee? sugar? Like many small employers I provide staff (and myself obviously) with the basic facilities of small refrigerator, microwave and toaster plus a few plates, bowls, knives, forks and spoons. They can also drink for free all the tea, coffee, drinking chocolate, or choice of a couple of cordials, that they can be bothered to make. Oddly enough the provision of free drinks is a highly regarded perk by employees and the cost to the employer is quite modest. It also gets rid of the wretched business of staff pooling funds to buy tea and coffee and milk supplies and the often remarkable amount of time taken up by organising this and the friction created by slow payers...
some items which might not sound like consumables actually are. For example electric kettles from all price ranges seem to have a strictly limited life span especially when being used by several people. At one time I had no water heater in my shop and I was always replacing the kettle because we were also using it to heat all the water for cleaning the shop and washing up the mugs.