Costings for campaign promises in the South Australian election have been released by Labor and the Liberal party, but the SA Best leader, Nick Xenophon, has declined, arguing the party’s primary role will be to hold the others to account.

According to the Labor treasurer, Tom Koutsantonis, Labor will outlay $550m due to new commitments, separate from the nearly $2bn in “investing expenditure” covering projects such as level crossing removals.

Election promises from the Liberals would cost $300m a year, largely covered by budget cuts including 1.7% in efficiency dividends across most government departments. The Liberals would also spend $449m on new capital works.

The parties have copied or matched each other’s commitments in some areas, so here are the major points of difference:

Energy and the environment

If the Labor premier, Jay Weatherill, is reelected, $100m in interest-free loans will be provided for 10,000 home battery or solar systems, as well as $24m in grants and loans for the Crystal Brook “hydrogen superhub”, and $32m in loans and grants for a Tesla virtual power plant scheme involving 50,000 home battery storage systems. The new 25% energy storage target will be backed by a $20m subsidy. Labor would also invest $28m into a network of parklands and walking trails.

SA Best leader Nick Xenophon with a store owner outside the Campbelltown shopping centre in Adelaide on Thursday. Photograph: David Mariuz/AAP

The Liberal leader, Steven Marshall, would put $200m into a fund for grid connections with other states, including a second interconnector to New South Wales. The Liberals also promise $100m in support for 40,000 home battery storage systems.

SA Best would establish a not-for-profit energy retailer, and commission a $5m review into restoring beaches.

Economy

Labor will invest $350m to develop the old Royal Adelaide hospital site for future industries including renewable energy and AI, and $35m into rolling out Australia’s fastest internet across the Adelaide city centre.

The Liberals would spend $60m on a culinary school at the old Royal Adelaide hospital site, which would also house an Aboriginal museum and an innovation hub. A Marshall government promises payroll tax cuts for small businesses, at a cost of $44.5m per year, and to reduce the Emergency Services Levy in a way that yields annual savings of $600 for a home worth $450,000, costing $90m per year. The party also plans to cut land tax, at an estimated cost of about $32.3m a year from 2020-21.

SA Best has pledged to make emergency services personnel exempt from the Emergency Services Levy, and to cut it for everyone else. Xenophon would also exempt small businesses from paying payroll tax on the wages of up to five new employees. SA Best plans to introduce a levy on pokie venues that don’t have live music.

Healthcare

Labor has commited $30m to a hospital for eye treatment, $22.7m to mental health, $15m to disease prevention, $5.5m to suicide prevention, and $4m to training chronic medical condition nurses.

The Liberals will invest $40m in shortening elective surgery waiting lists, and at least $14m on a trio of aged care facilities. New health investments will be funded by an efficiency dividend of 0.75% in current healthcare spending. Frontline roles such as doctors and nurses will be “quarantined from the efficiency dividend in a similar way” to that contained in the Weatherill government’s recent mid-year budget review.

SA Best is calling for a royal commission into healthcare, and proposes investing $25m into palliative care and $5m into home clinical trials for patients with rare forms of cancer.

Liberal leader Steven Marshall (right), SA Best’s Nick Xenophon and Premier Jay Weatherill during the final debate. Photograph: Tracey Nearmy/AAP

Infrastructure and transport

Labor is spending big in this area, promising $1.33bn to fix up seven level crossings, $538m in building tram lines out to north Adelaide and Norwood, and $150m each for a new ports authority and construction of 600 housing trust homes. Infrastructure savings will come from cutting SA Water’s budget to the tune of $55m over four years.

The Liberals will scrap the tram expansion plans, and instead spend $37m on allowing trams to turn right onto North Terrace, and $20m on the business case for a rail/airport freight link at Monarto. The party pledges that 30% of mining royalties will be directed to regional infrastructure projects. A Marshall government would establish an agency to independently consider infrastructure needs, in a bid to end government pork-barrelling, with an initial 10 projects to consider, including an underground rail link.

Xenophon has proposed a project costing between $125m and $150m to turn the old Port Stanvac oil refinery site into a mixed-use housing development, suggesting it could pay for itself if done right. SA Best will also spend $11m on rolling out a locally invented stormwater capture technique, and provide free public transport to seniors and a $10,000 handout to taxi drivers.

Education

Labor has pledged $100m of Tafe investment, $70m for laptops for public high school students, $37.5m for children’s centres, and $6m for natural play areas at schools.

Instead of Tafe, the Liberals would put $100m into 20,000 new apprenticeships, and contribute $12m to school sport.

SA Best would invest $3m per year into community education and gambling help services.

Governance

Labor would save $41m by cutting public service executive numbers by 10%, and save $60m a year by “driving a harder bargain” on government stock and materials purchasing.

The Liberals pledge to save $75m by reducing the use of consultants and contractors, $15.7m in cutting ministerial staff numbers, and $15m in reduced advertising and communications expenses. A Marshall government would crack down on some government perks, removing three chauffeur-driven cars from the ministerial fleet and banning “long boozy lunches at the taxpayers’ expense”.

SA Best is seeking to ban chauffeur-driven cars from government entirely. The party would introduce legislation to cut the House of Assembly from 47 members to 34 and the Legislative Council down from 22 members to 17. Xenophon would additionally provide an extra $1m in funding for the Commissioner For Victims’ Rights.