In reply to tehmarks:
Swapping picks on axes is fine and using the same axes for multiple styles of climbing works great. However, I've never found swapping front points to work out particularly well with crampons. Anything used regularly for mixed gets seriously blunted all round and just adding new front points doesn't miraculously resolve problems with secondary points and the rest of the crampons.
The OP might fair better if he is mainly climbing and mountaineering outside of the UK (where mountaineering routes and approaches on icy paths tend to be particularly hard on crampons) but almost all of the keen UK climbers and mountaineers I know have multiple sets and at least try to keep one set reserved for harder ice.
That said, what someone climbing half a dozen routes per year can get away with, won't work for someone wearing crampons for fifty, sixty or more days per year.
As with most things (boots, clothing, ropes), a "one size fits all" solution is superficially appealing and suits some people, but do enough climbing and mountaineering and the disadvantages quickly become apparent. You also ultimately realise everything is a consumable and the overall cost is identical whether you own one pair of crampons (or boots, or ropes) or three.
I stand by the main thrust of my advice - people should buy the kit that best suits what they are doing NOW, not what they might hypothetically be doing in the future.