You also need to factor in that the minimum wage is rising every year, the personal income tax rate is rising (they pay less tax) and the person on the spouse visa can then also work too and have their own tax allowance (they pay less tax with 2 working than just one person working).
True, but if fees keep going up by 25% every year, then those much smaller increases in minimum wage and tax allowance will matter little to the overall percentage paid. As for the immigrant spouse's income, while its a common reality that the immigrant spouse is also working, it's clear from the immigration rules (only counting the sponsor's income the first time around) , that the government does not assume this when formulating the rules.
The main thing here is that it is obvious that this is going beyond running costs, or, at the very least, that the government has deluded itself/the public into thinking that immigrants are the only people who use/benefit from border controls and thus should be he only ones who fund it.
Sent from my iPhone using Tapatalk