My £0.02:
A/C is a creature comfort, hence it's importance is very much a matter of personal opinion. Speaking for myself, I find it's a marvellous feature and offers enormous benefits in terms of comfot & convenience in exchange for a small (not significant IME) loss of economy. I'd be reluctant to buy another car without it and I certainly value it more than electric windows, central locking or even PAS.
A pollen filter is very much the same; a convenience feature, not strictly necessary, but very nice to have especially for hayfever sufferers such as myself where, combined with the above feature, it really does make a difference.
The reason I've heard that the A/C breaks down with lack of use is because the seals become starved of lubrication and contract, thus allowing the refrigerant to escape. I've run an A/C equipped car for several years straight without ever needing so much as a regas, simply by making sure it's switched on for a couple of minutes at least once a week, so it's not exactly costly to maintain. However, *if* for whatever reason you don't like A/C, it will do no harm whatsoever to simply ignore it's existence and continue to do so after it ceases to function. ;-)
Stu