Eh... Or they're not mature enough to talk to their partners like adults and make bad financial decisions. £2500 is a ton of money for some people, and just like any personal luxury purchase, tons of people overextend themselves because they feel like they "have to have it" and/or "deserve it" without discussing what might be a bad decision as a unit.
Even I, for whom this amount isn't a huge deal, know tell my wife to expect a charge on our card lest she think it's fraud or thinks I've gone squirrelly buying a £2k+ video game toy (for which she would have a very valid point). For others, it's a more inportant discussion to be had about budgeting, savings, and the value of things.
Going OT a bit but this is why my wife and I have separate accounts for our own purchases and a joint account we pay into for household bills. As long as the bills are paid, no issues with silly PC toys.