To go mad trying to find 3'x7' bedding for uni fresher?

[BengalGal]

DD has a dormitory place where the beds are 3' by 7' feet. I see two places on the web that sell sheets like this-- a cheap company called NTBAY, and they only have sheets, no mattress topper or protector, and one that's super expensive called Victoria Linen. Like 50 for a single sheet.
Is there anywhere to find used long bedding?
Or anywhere where you can actually see if it's crap quality or decent?

Help Please oh wise mums in my phone.

I don't know if they are any good, but this one came up first: indreamsbedding.com/collections/3-x-7-bedding

Can you find 7' stuff in the wrong width? It doesnt matter if a sheet is too wide - you just tuck in the excess (had stupid sized beds for the kids in a rental, they had double bottom fitted sheets and toppers, just tucked the excess topper down against the wall, and tucked the excess sheet in.)

Just put a bigger sheet on it! I stick double sheets on single beds all the time!

Use flat sheets rather than fitted. These will fit.
www.amazon.co.uk/AmigoZone-Cotton-Percale-Thread-Sheets/dp/B07DMB4HSF/ref=sr_1_9?dchild=1&keywords=Super%2BKing%2BFlat%2BSheets&th=1&tag=mumsnetforu03-21&qid=1629635680&sr=8-9