The honest answer to what a pottery kiln costs is that the listed price is one of four numbers. The others are the electrical work, the furniture and the delivery, and for a hard-wired studio kiln they can add a substantial fraction to the total.
The four numbers
The kiln itself, priced by chamber size and rating. The electrical installation, which is nothing for a plug-in machine and a real cost for anything larger. Kiln furniture, meaning shelves, props and kiln wash, which is consumable. And delivery and positioning of a heavy, awkward object. Budgeting all four from the start prevents the common experience of a kiln that arrives and cannot be used.
Plug-in against hard-wired
The plug-in bracket is the whole cost for many buyers and it is genuinely useful equipment. The step up to a hard-wired studio kiln is not simply a bigger price tag on the same purchase; it introduces an electrician, a possible consumer-unit upgrade and a fixed installation, which is why the two brackets should be compared as different propositions rather than as points on one scale.
Running cost, calculated
Kilowatt rating multiplied by hours at or near full power multiplied by your tariff. A schedule is not at full power throughout, so this overestimates, which is the right direction for a budget. Firing full is the one lever that reliably reduces cost per piece.
What people get wrong
Underestimating furniture and overestimating electricity. Shelves and props for a studio kiln are a serious purchase and they wear out; the electricity for a firing, while not trivial, is usually less alarming than expected once it is actually calculated rather than imagined.
Questions people ask about pottery kiln
How much is a pottery kiln in total?
The listed price plus electrical installation where needed, kiln furniture and delivery. For a hard-wired kiln those can add a substantial fraction.
Do I need to rewire for a kiln?
For anything above about three kilowatts, a dedicated circuit is needed. Whether that is easy depends on your consumer unit and the distance.
How much does each firing cost?
Rating times hours at power times your tariff. Filling the kiln is the main way to reduce cost per pot.