@Charpar:
Hmm... quiet a bit of a tough one...
Serious, for a real trip to the Swiss mountain passes (and some Italian/Austrian ones as well) you should at least calculate 4 days.
I live in the Zurich area and would be happy to help you out with any accomodations in the southern/mountainous part in Switzerland. I can also provide you with some useful info regarding weather and and/or street information (keep in mind that under worst circumstances passes in the Alps still can be closed in May even in June because of snow).
generally speeking, hotels in Switzerland are rather on the steep side. calculate at least between 60 and 100 swiss francs per night/person. that would be between 50 and 85 US dollars and 25 and 42 british pounds for a rather simple hotel. this can increase up to 30% more for a stay in a "better" (read more than 2 stars hotel), depending on location this can even get higher.
also, whenever possible try to come during the week. on weekends traffic can be a problem on some passes (most the well known and bigger ones). be also aware that local police in some cases is not very bike friendly. speeding will be prosecuted; keep in mind that your bike must be legal to be on the roads. there are police checkpoints on the well known bigger passes (mostly when the wheather promises a perfect bike day) on weekends, so be warned.
a suggestion from my side would be to base camp somewhere in the Engadin valley (not in St. Moritz for obvious reasons), stay there for one or two nights and then head on further south. from there the stelvio pass, bernina pass, oven pass, albula pass, maloya pass, reschen pass are all reachable in less than 2 hours.
Happy crashes,
Torino