Obtaining best deal / protection through T&C’s?

Hi

Have been doing some research prior to jumping into the property market.

Head spinning with so many options in regard to loans. Valuable advice of a general nature much appreciated.

I've been to see my bank, spoken to a broker, and looked on cannex. The rates seem to vary wildly, even for the basic products – which are what I think will suit me best.

Have been looking at a fixed rate, the best I could come up with was through an online lender – the bank and even the broker were nowhere by comparison, and they say they wouldn't be flexible.

In reading the terms and conditions on the loans of the online lender, it says that extra repayments are allowed up to 10k pa. The conditions also state that they can be changed at any time.

My question then is; can the terms of the contract be negotiated – ie ensure that this extra repayment can be guaranteed (as I don't want to be penalised for early repayment down the track if the lender decides to change this clause)?

Secondly any advice in obtaining the lowest cost of repaying the loan amount – looking at for example borrowing $250k the total amount to be repaid over a 25yr term varies from $530k-$600k (and that's the best deals!)

Thanks in advance
Ben.