For those more or less saying that you can't please some people, the current rules are such:
If you, as a British person, fall in love with, marry, and want to live in the country of your birth with a person who happens to be foreign, you must be earning £18,600 a year in order to even be eligible to sponsor them for a spousal visa.
You must first apply for leave to remain, which is £649 for a postal application or £1049 if you apply in person (if you apply by post it can take up to 8 months or more to receive an answer and both of your passports must go with the application). This gives you leave to remain for a whopping two years.
You must then apply for further leave to remain, with the same cost attached.
You can finally apply for settlement five years after your initial application, with - you guessed it - another application fee.
Finally, after all that, citizenship is just over £1,000.
Bear in mind that during all that, if you (the British citizen) lose your job or if your salary changes in any way, your partner's visa may not be renewed as you no longer satisfy the income requirements. During that time you won't be able to plan your life more than the next visa application ahead, and you certainly won't be able to save for a mortgage, because every penny you have is going towards these fees. And the gov.uk guidance on the process is as clear as muck, so be sure to save for some lawyers' fees whilst you're at it -- because if you mess up that form they will reject your application, you won't get the fee back, and much more significantly you will have to choose between living in a different country from your partner, or uprooting your entire life and leaving the country you were born in - if, that is, your partner's country allows you to emigrate there.
£500 for the NHS may seem fair. But in this context, I don't think the OP is BU. It's the straw that breaks the camel's back, and it's part and parcel of a political attitude that sees immigrants as numbers on a spreadsheet rather than as individuals who contribute in a wide range of ways to the country, not least of all financially.