Like the people above said, depends on your lifestyle.
I moved over by myself to Brisbane in 2012 on a 457 visa, within 2 days of arriving I found a room in a shared house at $220 a week (all bills included) and that was a cheap way to live until the job was sorted and I had a few pay cheques. My partner joined me later and we rented a 'really' nice 2 bed fully furnished apartment for $595 a week, so make short term sacrifices and then live more 'luxuriously' when your circumstances allow.
Within a week of arriving I had a $10K credit card and car lots offering cheap(ish) credit on used cars so that is an option. I was surprised that without any credit history, and being a temporary resident, I could take out car loans within a week of arriving, plus interest rates are current at, or near, historic lows (I think, don't quote me on that!), so although you pay a premium for a loan it is not so bad at the moment.
A car is nice, but not essential initially as major cities are well served with public transport and I went two months before saving the money for a car.
Consider also the initial costs before you even apply for a 190 visa: skills assessment and points advice letter (Approx $1400), Notary for skills assessment docs (£60), IELTS (£139). You then have the 190 Visa costs, UK police check (£45), Medical (£370), shipping (approx. £400 for 7 big boxes) and cost of one way flight.
if money is tight and your do not have complex medical issues, do the application yourself. It is not difficult and will save you a fair amount of money that you can then take with you to Aus, or use to move out that bit sooner.
You need to check your profession but I assume as a chemist it will be VETASSES (I'm a physicist and it was for me), VETASSES have a 12 week processing time on applications and you cant apply for a 190 visa until you have a positive skills assessment. Consider the wait for the skills assessment in your plans. You also need IELTS before applying for the 190 visa, so consider the wait for that also.
When I moved out on a 457 visa I had around $2000 in the bank, but walked straight into a paying job. If you don't have much money before your move network, network and network some more on LinkedIn etc. to get yourself known and tap any existing contacts you have in Australia, regardless of how spurious the link. Find UK expats in Aus on LinkedIn in your profession and reach out to them, they have travelled the same road as you and from my experience prepared to really help you out with industru contacts and introductions to hiring managers etc. and insider info about jobs not advertised. You can get a one month free trial on linkedIn and that lets you research potential contacts and send them inMails.
Good luck!