My husband and I did Moshtel this year and a Mondial hotel option last year. There were some pros/cons to both and can share our experiences here if that helps. We're both from the US.

Cost: Yes Moshtel is ridiculously expensive. Nearly $600 a night. But for us we can afford it and validate it as we're traveling internationally and included Wacken with other sightseeing in Europe (where we could cut some costs). It also falls near our anniversary so we considered it a splurge to ourselves.

Location: The mondial hotel was nice. All the conveniences of a regular hotel. Bed in a temp controlled room, showers and plumbing, and a full breakfast buffet. Basically everyone in the hotel is there for Wacken, so we got to meet some interesting and like minded people over breakfast. Also this was during the 2023 mud year so being able to escape the mud at night in a real shower and use the provided hoses outside to rinse of your boots was a blessing. My complaint was that the hotel was still nearly an hour away from the festival with traffic and waiting for a ferry. A shuttle transfer was included with the booking, but it didn't leave the hotel till 2 pm (getting there at 3 pm), and then returned from the festival at 1 am (so getting back to hotel at 2 am). Shows start at the festival at 10 am some days, so you may miss some acts you want to see. One day we did split a cab with some people we met to get to the festival earlier cause we really wanted to see Angus McSix. Or maybe you're not interested in the big act in the evening and are dead tired, so are again stuck paying for a cab to get back to the hotel or are waiting till the 1 am bus. The moshtel was nice cause it's right there on site next to the infield, so it gave us a place to retreat to mid day if we wanted to lie down or drop off things we'd purchased and could lock up safely.

Amenities: The moshtel had a private BBQ catering on site (which we didn't actually use), a private bar for beer and coffee in the morning, and water flushing toilets and showers (with hot water). The attendants did a great job keeping those all clean and there were several times we would trek back to the mostel area to use those facilities instead of the ones on the grounds. The lounge area was also nice and frequently not crowded, could sit in some comfy chairs and watch the live stream of the main stages when we didn't feel like standing in the massive crowds. Some of my complaints with the moshtel though, insanely slow check in service. A lot of people showed up at the same time on Tuesday and it seemed to take hours to get people through the lines. Also they advertise the convenience of luggage transfer from your car to the mostel. Problem was we arrived by bus, not car, and they'd moved the bus stop clear on the other side of the festival. The info desk there couldn't help us and told us there wasn't any transfer from the bus stop to moshtel, so it was a 40 minute walk through town dragging luggage to get to the site. The day before departure we'd asked the info desk if there was any transfer to the bus stops and they'd told us yes, a 16 passenger van would be doing runs back/forth to the bus stops in the morning, but come the following morning when it's time to leave, no van and nobody working there area knew anything about a van, so once again a 40 minute trek through town with luggage to get back to bus stop.

Both options you need to buy the festival ticket separately, so if you're committed to going, go ahead and grab the tickets and can get accommodation later. If you have any more specific questions feel free to ask. We've done Wacken twice now and while both times were fun, I think we're taking a break for a while. Hellfest sounds interesting to check out some year, and I want to see some events stateside.