Not only the up front cost from a breeder, but also the ongoing maintenance of having one.
Our rescue Cavalier and our cav we got from a breeder were both around $1500. As far as maintenance goes, this breed is pretty needy – they tend to be picky eaters with sensitive tummies which requires a special diet (which can be more pricey). They are also prone to health conditions like heart murmurs and dental issues, so be prepared for the unexpected. Luckily we have health insurance for our dog (had it since he was a puppy) – the earlier you sign up the less the premium is and so glad we got it because we’ve hit the deductible ever year (so it’s been worth it and then some!)