UK chancellor Healey has a rather unenviable task at hand today. He is expected to deliver a budget that keeps households happy, businesses afloat, and bond investors calm. All while trying to convince everyone that the government isn't running short of money. Well, good luck with that.It is definitely quite the juggling act for his first autumn budget. And with borrowing costs still elevated and fiscal headroom shrinking, there's not exactly much room for him to get creative.So, what goodies can Healey realistically pull out of the bag today? And perhaps more importantly for markets, it is the question of who's going to end up paying for them?Here are some of the key measures to watch out for:Bank tax hike: A potential reversal of the bank surcharge cut from 8% to 3%, which could raise over £2 billion annuallyOnline marketplace taxes: Requiring platforms like Amazon and eBay to collect VAT from more UK sellers, potentially raising £1 billion to fund business rates relief for smaller shopsEnergy bill relief: Over £1 billion in support for poorer households, including a possible £100 increase to the existing £150 Warm Home DiscountFuel duty freeze: Another extension looks likely, although that could cost the Treasury up to £2.7 billion annuallyHousing support: A proposed 20% equity loan for first-time buyers purchasing new-build homes, requiring deposits of just 2.5%Now, that is quite the shopping list for someone with limited fiscal room to work with.The government's already strained fiscal position isn't helping with the situation, with its fiscal headroom potentially being halved from £24 billion to around £12 billion amid rising borrowing costs. So, that just means gilt traders will have plenty to scrutinise today.Besides that, the OBR forecasts and borrowing projections could arguably matter more than the spending headlines. A more credible fiscal plan could offer some relief to gilt yields, particularly at the long-end of the curve. However, any suggestion of unfunded spending will only risk another bond market tantrum and that won't be a pleasant sight.As we look to the budget announcement later (expected at 1230 GMT), do keep a watchful eye on how the energy relief measures might influence inflation expectations and in turn BOE rate hike pricing.For Healey himself, I reckon a boring budget might actually be a win for his political standing. But whether or not markets agree is a whole other matter. This article was written by Justin Low at investinglive.com.