The price of a cruise holiday often includes meals, a comfortable cabin and a selection of entertainment onboard. But there are usually additional costs, too – and these can quickly become expensive, especially if you aren’t a regular cruise passenger.Fortunately, cruise expert Jeannine Williamson has revealed what is worth spending money on during a cruise trip, and what to avoid. Cruise holidays are often both incredible and expensive – but Jeannine Williamson knows what to spend onFrom food, drink to splurging on a balcony room, Williamson shares her take with iNews on each aspect of the voyage.Excursions For Williamson, shore tours ‘undoubtedly enhance a cruise’ if you haven’t been to the destination before.Prices can vary greatly and the expert notes a half-day buggy tour in Turkey can cost £60, while a seaplane ride in Alaska can set you back a whopping $5,800 (£4,280). Tours operated by third parties are usually cheaper than booking directly with the cruise company.The cruise line will emphasise that if one of their tours runs late, they will wait at the port for you, but Williamson argues it’s possible to find reputable companies externally too.Highly-rated Viator, operated by Tripadvisor, has a range of excursions for many different destinations.For example, in the major cruise port of Messina there are more than 100 tours available on the site with prices starting from £37. Wi-Fi packages When on the water, a service called Cellular at Sea can be used but it is often expensive.Instead, Williamson recommends purchasing one of the cruise liner’s packages which she says is often ‘much cheaper’.Some companies offer free Wi-Fi, including Viking and Silversea.On other ships, prices range from around £8 a day on Ambassador cruises, £10 a day with P&O and Carnival offer packages starting from $20.40 (£15.20) a day. If you’re looking for some private, outdoor space, a balcony cabin could be worth splashing out onDining and drinksTreating yourself to a speciality dining restaurant on the ship is ‘a real treat’ according to Williamson.However, she doesn’t tend to book on short cruises that are less than five days because of the choice already available.Williamson recommends the Chef’s Table on Ambassador Cruise Line, where you can enjoy a three-hour private dinner for £89. As for drinks packages, the expert urges holidaymakers to carefully calculate how many beverages they might buy compared to the price of the package.For those who enjoy a few tipples, it might be worth the daily fee, but if you don’t intend to go wild, you may be better off without. Balcony cabinsWilliamson argues that splashing out on a balcony cabin is ‘a no-brainer’ for most passengers. A windowless cabin is cheaper and great for those who don’t intend on spending a lot of time inside. Speciality dining packages are not always worth it on a shorter cruiseCertain cruises aren’t always worth the extra cash on a balcony either, the cruise expert says a voyage in the winter with a window room around northern Europe, for example, can be 25 per cent less expensive. But, a balcony can provide a private, outdoor space to get away from the busy communal spaces – it depends what you’re looking for. What to avoid paying for?Williamson says the spa isn’t always worth it. She’s experienced inflated prices paired with having to tip – it can be an expensive thing to do and often ‘underwhelming’.Photo packages are also something to avoid. The expert reveals this is one thing she ‘never buys’ and argues passengers can take good-quality photos on their phones.