What do small small home service businesses spend on SEO and Google Ads every month? I'm trying to set expectations.....

Hi.... I am starting a small buisness that installs, replaces, repairs and unclogs toilets. This is a very niched down business. I found a few people in the US who are doing the same thing and they install 4-8 toilets a day. Unfortinatly most of the clients are new... not repeating.... so I need to market myself. For those of you who deal with home service businesses.... how much do you see your clients spending on SEO, Google Ads and marketing every month?