Based on experience of 'budget' batteries for my Dell XPS, they're all the same with a different label and they don't work properly. Look for a decent set of reviews for the supplier.
Pay the £88 itll last a long time , 3rd party lithium batteries installed by randoms are my irrational fear based many off all the e scooter fires
Can you get the old battery out easily? Many laptop manufacturers don't make it straightforward nowadays.