Mike and everyone else on this section have much to be proud of with their attitudes to developing commercially driven businesses and if I am honest I have not seen this question raised (from this angle before) and from my own perspective I started a pressure washing service from a residential window cleaning round, as an add on. I am confident that Mike meant no malice with his response.
He is big enough to defend his own actions though, as he has done.
I started with a 5.5HP petrol machine that lasted till it blew up cleaning a commercial roof. My attitude is to go and offer any service from a slightly different angle.
If you offer a service, with equipment that the homeowner can go and buy from the local shed there doesn't, from my perspective, seem to be anything better than in that.
You don't have to spend a great deal of money to have a petrol machine and a wheeley bin that can be put in the van for the odd job. I am sure for not a lot more money than you will be paying for the yellow throw away machines. The other side of it is that if the cheap machines go wrong they are meant to be thrown away, something with a petrol engine can be repaired and will give years of service.
Whatever you decide we are a good bunch down here - honest
Rob