Well, to answer your accommodation question, you can try caribilik.com, it's a site where people can find cheap accommodations, kinda like a homestay.
As for weather... I think it varies, Malaysian weather are hot and damp all year round, and the weather can hardly be predicted. It's just either really hot, or raining alot.
For beaches, personally I think hotspots like Port Dickson are overrated. Beaches like those in secluded spots of Terrenganu are great.
Prices- Food are CHEAP in Malaysia! If you want to enjoy pure Malaysian food, skip posh restaurants (unless it is recommended!) and go for food stalls, just beware where you eat though, there are unhygienic food practices in some areas. Generally, an average meal would cost you RM10-20, converted to usd, should be no more than 6usd. There's alot of delicacies you really shouldn't miss out in Malaysia!