Question Source of aluminium, brass etc

Maybe a little offtopic, but I can`t post about experience in milling aluminium if I can`t get any.
So could anyone please recommend a good online source of "Stepcraft size" pieces of aluminium alloys and other soft metals. Would like to find a shop where you enter the dimensions and type of alloy you want and immediately see the price and shipping cost based on weight or something like that. Local dealers want to transport stuff in big trucks, price enquiries etc.

I use metals4u.co.uk

I tend to buy in bulk from China, alibaba is a good place to start. You do have to buy in bulk though..

I bought a selection of 300mm x 210mm (roughly A4) from metaloffcuts.co.uk

Brass Sheet Metal 300mm x 210mm x 0.5mm
Brass Sheet Metal 300mm x 210mm x 0.3mm
Sheet Metal, Copper, 300mm x 210mm, 0.4mm
Bright Polished Aluminium Sheet 300mm x 210mm x 1.2mm
Brushed Satin Aluminium 300mm x 210mm x 1.2mm

About £5 - £7 per sheet which seems expensive to me but I just wanted small samples to experiment with. I've not yet experimented with any metal.

Postal charge was £7 (UPS).

Thank you for your answers so far. Here is something I am looking for, but I would like to see a bigger selection of alloys and tempers: https://www.aluminium-online-shop.de/de/shop-aluminium-kleinstmengen/Bleche---Platten-_-4/index.html . Mainly looking for 7075-T6 and some 6000 series aluminium alloys + some brass and maybe even bronze (if the machine can handle it).