This feels like some weird purity test or something. Sometimes am unexpeted hook up happens and it's better to have a condom ready than have unprotected sex with a stranger. You aren't complaining about having sex in the same bed as her previous partners, so why would unused condoms be any different?
That's my point - those are not "unexpected hook-ups" (I never feel comfortable with those), those are events in a relationship they could absolutely prepare for, and something that normally comes with a greater level of intimacy.
Changing a bed is unreasonably costly, materially and financially, besides, bed is not necessarily associated with sex.
Getting new condoms is a matter of spending beer money at a nearest pharmacy.
So if she had been out of a relationship for, say, a year, and had bought a box at the start of the time, used half of them on different partners, and then used one with you it'd have been fine? At least from the condom perspective, never mind that she has casual sexual encounters and that's never cool. Good luck on your gymnastics journey.
Considering you went straight to cost, the vibe I'm getting from this is you'd be happier if they did replace the bed. Along with everything else.
I don't know how old you are (you sound on the younger side), but I can tell you this is something that will get worse as you get older, not better. I'm someone that used to have a jealousy/insecurity streak with my partners and I worked on it. Something to consider.
I said already I don't have insecurity about past partners or retroactive jealousy. It's just gross to me.