If you want a short term apartment you will have to offer more than the asking rental which is based on a year's lease. You will also have to pay the rent in advance along with a refundable security deposit. Most likely one month for a 3 month term. It is a relatively quiet period at present so it may be easier to get some landlord's to agree to short term.
Low budget places are usually on the books of local agents in the area that the apartments are. Most local landlords can't read or speak English so they won't be posting online. Find the area you want to live and look for the newest buildings as this is where the local agencies are. Most of their business is sales but they will have a few places for lease on their books or will call a fellow agent in the area.
Don't be surprised if they aren't falling over each other for your business because they won't gain much for short term low budget. But a few local agents will be of help, I am sure.
You will be asked to pay a 35% of one month's rent as finders fee which is based on a year's lease so you will pay pro-rata.
Have a look at our Advice on Leasing to help with negotiations, offers, contracts etc.
Good luck with the hunt!
Adrienne
http://www.shanghaiprops.com