No the purchaser pays and normally depending on what I find let’s say a complete rewire the seller then deducts the cost of the work from the selling price. Sometimes if upgrades are under £1k say the seller may swallow it to push the sale on.
I did a recent one for a rather famous actor let’s...
Most lenders are asking for a EICR (electrical cert) an additional cost even if the sale collapses. I do loads for house purchasers these days.
I would say about 2k for everything else as a rough estimate.