i was meaning your attitude will change, you will WANT something faster regardless of wether or not you can afford it.
most people start off saying "oh asw long as it gets me from a to B" but not even being able to overtake tractors, or having to make people get out so you can get up steep hills gets annoying very fast, it becomes much an issue of practicality as opposed to speed.
Anyway, what insurance company are you getting quotes from? have you added your mum to the policy? have you tried elephant? they are BY FAR the cheapest around.
insurance WILL be high as you will be a new driver and theres nothing you can do about it, so just grit your teeth and pay it, if you have yourself a NCB after a year it will drop significantly, then again after 2 years and then it really doesnt seem so bad
im 21 with 1 years NCB and 3 points on my licence on a group 7 car and i only pay £425 fully comp with hire car cover (not courtesy car, they are different) and a ditsy £150 excess.
Just have to bide your time buddy,