Spraypaving or Clean Concrete?

I have a situation with the driveway (part of which has to be dug up and replaced) and a dirtyish concrete slab under the pergola at the back of our reno. We realise the final decision will be based on reno cost / budget and target market, but has anyone had experience of spray paving rather than cleaned concrete, with direct regard to the appeal factor to potential buyers? Cost approx $27+ per sm to spray.

Ian